1Introduction

This manual explains the installation, configuration and usage of the payment module for xt:Commerce 3 and Computop.

Before beginning with the installation, please make sure that you are in possession of all necessary data:

  • You should have received a Merchant ID from Computop for the test account. Furthermore, you have received the corresponding user name and password
  • Encryption password and HMAC-Key
  • An Analytics Password which you require for logging into Computop Analytics
  • xt:Commerce 3 payment module by sellxed.com/shop
  • Access data to your server and shop

In case you don't yet have a contract with Computop, you can gladly acquire it directly through us.

1.1Process of the Installation

In this document you will find all information important for the installation of the module. It is important that you strictly follow the check-list. Only by doing so, can a secure usage in correspondence with all security regulations be guaranteed.

  1. Basic configuration of the server including the setting up of the notify script
  2. Configuration of the basic settings of the payment module
  3. Configuration of the payment methods
  4. Carrying out of a test purchase with the attached test data at the end of this document
  5. If the test was successful, your account can be activated
Installation Service

Our payment plugins should have per default the correct settings for most of our customers' preferences. That means once you have entered the required credentials in the plugin configuration to connect your account to your website, the plugin should be fully operational. Should you be willing to receive detailed informations on a setting you do not know, you may contact our support team who will be able to assist you further.

Our support team is at your disposal during regular business hours at: http://www.sellxed.com/support. Furthermore, you have the option of ordering our installation service. We will make sure the plugin is installed correctly in your shop: http://www.sellxed.com/shop/de/integration-und-installation.html

.htaccess Directory Protection

In order to test the module, any kind of directory protection or IP blocking on your server must be deactivated. This is crucial; otherwise the payment feedback of Computop might not get through to the shop.

2Configuration of the Payment Module and the Server

In order to perform the configuration of the main module of xt:Commerce 3, the following information is necessary. You should have received the information from Computop.

  • Computop Live Merchant ID
  • Computop Live Encryption Key
  • Computop Live Signature Passphrase

Enter the credentials directly inside the configuration of the main module. After you performed some test payments, you can switch between Live Mode and Test Mode.

2.1Configuration of the Payment Module

For the usage of the gateway in your shop, fill in all received access data at its corresponding place in the main module and in the payment methods.

Hidden Mode

Please Note if you use hidden this poses additional PCI requirements to your shop that have to be met. Get in touch with Computop to get additional information.

Also if you use Hidden in your Module please advise Computop that they are able to configure your paynow settings accordingly.

3Module Installation and Update in the xt:Commerce 3 Shop

3.1Installation

At this time you should already be in possession of the module. Should this not be the case, you can download the necessary files in your customer account in the sellxed shop (Menu "My Downloads Downloads"). In order to download the module in your shop, please carry out the following steps:

  1. Download the plugin. The download can be found in your sellxed.com account under "My Downloads".
  2. Unzip the archive you have just downloaded.
  3. In the unzipped folder navigate to the folder "files"
  4. For some shops there are different versions of the plugin provided. If this is the case open the folder which corresponds to your shops version.
  5. Using your preferred FTP client upload entire content of this folder into the root directory of your shop. For some shops there is a specific folder containing the plugins. If thats the case upload the plugin into this folder. Make sure that the folders aren't replaced but merely merged.
  6. If you haven't yet done so, log back into your shop.

3.2Updates and Upgrades

You have direct and unlimited access to updates and upgrades during the duration of your support contract. In order to receive constant information about available updates we ask you to subscribe to our RSS feed that we publish for your module. More information regarding the subscription of this RSS feed can be found under: http://www.sellxed.com/en/updates_upgrades.

We only recommend an update if something doesn't work in your shop, if you want to use new feature or if there is a necessary security update.

3.2.1Update Checklist

We ask you to strictly comply with the checklist below when doing an update:

  1. Always do a back up for your database and your files in your shop
  2. Use always a test system to test the update process.
  3. Wait until all the files are copied to the shop, clear the cache if there is one in your shop and then visit the configuration page of the main module so that the update process will be initialized.
Do not do updates directly in the live environment

Please test the update procedure first in your test shop. Our support team is able and willing to help you if you experience problems with the update process. However, if you decide to perform the update directly in your live shop there is the possibility of a downtime of the shop of more than two days depending on the availability of our support if you do not want to book our complementary support.

Depending on the version it could be that the database has to be migrated. We recommend you therefore, to perform the updates in times when the shop is not visited too frequently by your customers

3.2.2Update Instructions

Please always read the update instruction. They can be found on the plugin page in the shop under the section change log on the lower end of the page. If there are no special remarks, you can proceed by just overwriting the files in your system

4Module Configuration in the xt:Commerce 3 Shop

The configuration consists of two steps. The first step is the configuration of the main module with all the basic settings (cf. Configuration of the Main Module). During the second step you can then carry out individual configurations for each payment method . This allows for full flexibility and perfect adaptation to your processes.

Create back-ups!

Please create a back-up of the main directory of your shop. In case of problems you will then always be able to return your shop to its original state.

We furthermore recommend testing the integration on a test system. Complications may arise with third party modules installed by you. In case of questions, our support is gladly at your disposal.

4.1Configuration of the Main Module

You will find the settings for the module under "Modules > XT-Modules > Computop Base Module" . Install the module and click on "Open Method Configuration". A new window should open up. Enter the individual options such as described above in the configuration of the administration interface of Computop. Should one of the options not be clear to you, you can find further information by moving the cursor to the question mark. The most central settings are explained in more detail in this manual.

4.1.1Create Pending Orders

You have the possibility of creating pending orders. In this case a temporary order will be created with the status "pending payment". This allows you to reserve the item in your shop and to transmit the identical order number as in the shop to Computop. In the case when a customer cancels his or her purchase, the order remains in your shop - except if you activate the option "Remove cancelled orders". This makes sure that cancelled orders are deleted regularly. If you do not wish to create pending orders, simply keep the default setting of xt:Commerce. However, this also means that the reference number (payment ID) with Computop doesn't correspond to the order number in the shop. You are, however, free to use both options.

4.1.2Database Encoding

If you haven't selected UTF-8 as a default for your database, this might lead to encoding problems with parameters with special characters. In this case you must select the option that data is UTF-8 encoded before being sent to Computop.

4.2Configuration of the Payment Module

After having successfully configured the main module, you can find the settings for the individual payment methods in your shop under Modules > Payment Options. Each payment method is listed individually. Install the payment methods you wish to offer to your customers. You can carry out individual settings for each payment method and thereby optimally adapt the payment methods to your existing processes. The most central options are described in more detail further below.

By clicking on "Open Method Configuration" a new window will open up for the settings. Most of the settings are self-explanatory. You can get further information by moving the cursor over the question mark.

4.2.1Selecting the Authorisation Method

You can choose between two options of authorising credit card payments. By selecting one of the two under the option 'Authorisation Methods', you define how you want to process the individual payment methods.

Further information on the various authorisation methods can be found on our sellxed website.

Payment Processing

Please pay attention to the fact that you require the activation of further options with Computop in order to use some of the authorisation methods.

It may be that certain authorisation methods are not available for every payment method.

4.2.2Direct Debiting of Orders

The option "Capture" allows you to specify if you wish to debit payments directly or if you first wish to authorise them and the debit the payment at a later point.

Depending on your acquiring contract, a reservation is only guaranteed for a specific amount of time. Should you fail to debit the payment within that period, the authorisation may therefore no longer be guaranteed. Further information on this process can be found below.

Different settings between Computop back-end and module

It may be that settings saved in the payment modules overwrite settings saved in Computop.

4.2.3Uncertain Status Status

You can specifically label orders for which for example no 3D-Secure verification nor any other security mechanism was carried out. This allows you to manually control the order before shipment.

4.2.4Setting the Order Status

You can specify for each order what status they should receive based on the booking status. This concerns the initial status of the order.

4.3Shop ID

In the case of a multi-store set up (cf. chapter: Multi-Store), the parameter Shop ID identifies the shop's request and, therefore, redirects the feedback of Computop based on the shop ID.

4.4Order Prefix

With the option order prefix you can define your own order scheme for the transmission to Computop. This option helps you identify to which shop a transaction the back-end of Computop is related to. The tag "{id}" will automatically be replaced be the consecutive order number.

4.5Selecting the Authorisation Method

You can choose between two options of authorizing credit card payments. By selecting one of the two under the option 'Authorisation Methods', you define how you want to process the individual payment methods.

Further information on the various authorisation methods can be found on our sellxed website.

Payment Processing

Please pay attention to the fact that you require the activation of further options with Computop in order to use some of the authorisation methods.

It may be that certain authorization methods are not available for every payment method.

Alongside the introduction of PCI 3 there are additional certification requirements in case you are using the authorization method Hidden or AJAX. Please contact Computop for further information or switch to another authorization method.

4.6Direct Capturing of Transactions

The option "Capture" allows you to specify if you wish to debit payments directly or if you first wish to authorise them and the debit the payment at a later point.

Depending on your acquiring contract, a reservation is only guaranteed for a specific amount of time. Should you fail to debit the payment within that period, the authorisation may therefore no longer be guaranteed. Further information on this process can be found below.

Different settings between Computop and the module

It may be that settings saved in the payment modules overwrite settings saved in Computop.

4.7Uncertain Status Status

You can specifically label orders for which for example no 3D-Secure verification nor any other security mechanism was carried out. This allows you to manually control the order before shipment.

4.8Optional: Validation

Note: It can be that this option is not visible in your module.In this case just ignore this section.

With the option 'Validation' you can define the moment when the payment method should be made visible to the customer during the checkout process. This setting is relevant for modules where the usage depends on the customer's compliance with specific preconditions. For example, if a solvency check has to be carried out or if the payment method is only available in certain countries. You have the choice between these options:

  • Validation before the selection of the payment method: A validation verification is carried out before the customer selects the payment method. If he or she does not fulfill the requirements, the payment method is not displayed
  • Validation after selection of the payment method: The verification of the compliance occurs after the selection of the payment method and before the confirmation of the order
  • During the authorisation: The validation verification is carried out by Computop during the authorisation process. The payment method is displayed in any case

4.9Multi-Shop Set-Up

The payment module is designed for the usage of one Computop contract for several shops. It must be differentiated, however, between the case of an integrated multi-shop functionality and independent shops:

Figure 4.1: Multi-shop set-up
Licensing

In the case of independent shops, you require a payment module license for each shop. For scale prices, please contact us directly.

5Settings / Configuration of Payment Methods

5.1General Information About the Payment Methods

All sellxed payment modules are delivered with the most common payment methods. In case a desired payment method is not included per default, please contact us directly.

In order to be able to use a payment method, it must be activated in your account with Computop as well as in your shop. Information about the configuration of the payment methods can be found further above.

Below you can find important information for specific payment methods that deviate from the standard process.

5.2Information on Payment Status

For each payment method you can define an initial payment status (status for authorized payments etc.). You hereby define the payment status for each state depending on the processing type of the order (captured, authorized, etc.). It's the initial status which the order assumes. Depending on the mutation carried out by you, the status can change.

Important info regarding Order Status

Never set the status to Pending Computop or any similar pending status which is implemented by the module.

5.2.1Order status "pending" / imminent payment (or similar)

Orders with the status 'pending Computop' are pending orders. Orders are set to that status if a customer is redirected in order to pay but hasn't returned successfully or the feedback hasn't reached your shop yet (Customer closed window on the payment page and didn't complete payment). Depending on the payment method these orders will automatically be transformed into cancelled orders and the inventory will be cleared (so long as the Cronjob is activated). How long this takes depends on the characteristics of the payment method and cannot be configured.

If you have a lot of pending orders it usually means that the notifications from your webserver to Computop are being blocked. In this case check the settings of your firewall and ask the Hoster to activate the IPs and User Agents of Computop.

5.2.2Order status "cancelled"

Orders with the status "cancelled" have either been set to that status automatically due to a timeout, as described above, or have been cancelled directly by the customer.

5.3Payment Methods

The modules differentiate between the standard and the professional version. In the professional version, all payment methods available for Computop are integrated. With the standard version, however, you only receive the most common payment methods. Should a desired payment method not be available, please contact us directly.

5.4MasterPass Integration: What to keep in mind

If you integrate MasterPass as a payment method in your shop, you have two integration options: External and Standard Checkout. When using External Checkout, the customer does not have to provide address data during checkout. The customer only needs a MasterPass account and the data will be transmitted by MasterPass. In order to use this option as a merchant, you have to activate this payment method with Computop.

Please keep in mind, that using additional functions such as address transmission through MasterPass, may require the activation of the respective options through Computop aktiviert.

In order to use MasterPass in compliance with the MasterCard guidelines, please read the following information carefully before using this payment method.

5.4.1Integration Possibilities for MasterPass

MasterPass can be integrated as a normal payment method with redirection to Computop or as an external checkout.

5.4.1.1MasterPass as a Payment Method

If you like to integrate MasterPass as a normal payment method, activate the payment method as usual (seeConfiguration of the payment method). In this scenario the customer will first be redirected to MasterPass and then to the wallet of the issuer.

5.4.1.2MasterPass as External Checkout

If you integrate MasterPass as an external Chekout, you can minimize the steps towards the payment radically. The adress transfer and the creation of the account is processed via MasterPass. If you activate the external checkout, there appears a button in the basket with which you can jump after the login directly to the last step of the order confirmation. The creation of the account happens in the background.

For the activation of the external checkout go to Module > Computop Base Module > open Main Configuration . There you'll find all settings for the external checkout:

Figure 5.1: Activation of the external checkout.

MasterPass as external checkout is not for all cases available. If this point in the manual doesn't appear, please make sure to contact us.

5.4.2Checkout: MasterPass Learn More Button

When using MasterPass as a payment method for standard checkout, it is mandatory to link to the MasterPass Learn More Page. In order to do this, navigate to Payment Method Configuration. Paste the link for the Learn More Page into the field 'Description' for the respective languages. The field 'Learn More' will now be displayed when choosing a payment method.

We have already collected the most important links for you. You only have to copy and paste the links into the description field:

  • German:<a href="https://www.mastercard.com/mc_us/wallet/learnmore/de/DE/" target="_blank">Mehr Erfahren </a>
  • French:<a href="https://www.mastercard.com/mc_us/wallet/learnmore/fr/FR/" target="_blank">apprendre plus </a>
  • English: <a href="https://www.mastercard.com/mc_us/wallet/learnmore/en/DE/" target="_blank">Learn More </a>
  • Spanish:<a href="https://www.mastercard.com/mc_us/wallet/learnmore/en/ES/" target="_blank">aprender más </a>
  • Italian:<a href="https://www.mastercard.com/mc_us/wallet/learnmore/it/IT/" target="_blank">saperne di più </a>
  • Dutch:<a href="https://www.mastercard.com/mc_us/wallet/learnmore/nl/NL/" target="_blank">Leer Meer </a>
Figure 5.1: Example for entering a description (Magento). These settings are to be found in the payment method configuration for MasterPass.
Figure 5.1: The Learn More Page link should appear in the frontend.

Links for additional languages can be found in this document: https://developer.mastercard.com/...

5.4.3Additional information

General and additional information on using the MasterPass trademark and logo in your webshop are available in the official MasterPass Mechant Branding Requirement Document. which you can access here: https://developer.mastercard.com/...

5.4.4Code Adjustments for the MasterPass Integration (xt:commerce SP 2.1)

In order for the button "Pay with MasterPass" to appear in the shopping cart when using external checkout with address transmission, the following adjustments in the code have to be made. If you prefer to simply use MasterPass as a regular payment method without address transmission, no changes are necessary.

The files containing the necessary code adjustments can be found in the zip files in /changes/*.txt. Please paste the codes contained in these files into the location described below.

5.4.4.1Adjusting shopping_cart.php

Please copy the code snippet from the file /changes/shopping_cart.php.txt in front of the following code:

$smarty->assign('language', $_SESSION['language']); (ca. line 140)

5.4.4.2Adjusting templates/[current-active-template]/module/shopping_cart.html

Please copy the code found in /changes/shopping_cart.html.txt in front of the tag-{/if}:

5.4.5Further information

MasterPass with External Checkout cannot be used in combination with vouchers. If the customer wants to redeem a voucher, she has to go through standard checkout.

6The Module in Action

Below you will find an overview over the most important features in the daily usage of the Computop module.

Figure 6.1: Transaction Information

6.1Useful Transaction Information on the Order

You can find an overview over all the most important information of a transaction in all orders that have been processed with the sellxed module. Among others, this information allows for the definite attribution of the orders to their corresponding transaction, seen in the back-end of Computop.

Figure 6.1: Transaction Information

6.2Using invoice details of a processor

In the following context you can view or embed the "payment details" of for example an "Open Invoice" transaction:

6.2.1xt:Commerce 3 Order confirmation (E-Mail)

The "payment information" will be visible in the default "order confirmation e-mail" of xt:Commerce 3.

6.2.2xt:Commerce 3 Invoice (PDF)

This feature is not available by default in xt:Commerce 3 that`s why it can not be supported by the payment gateway module.

6.2.3xt:Commerce 3-Backend (Transaction details)

You can view the transactions details in xt:Commerce 3 under Modules > Modules > Computop Base Module > open main module configuration > (above) Transaction Management.

Figure 6.1: Transaction details within xt:Commerce 3.

6.2.4xt:Commerce 3 Success-Page

Due to technical limitations, it is currently not possible to display the "payment information" here.

6.3Trigger Payments in the xt:Commerce 3 back-end

With the xt:Commerce 3 payment module, orders can be triggered directly from within the shop, so called Mail Order / Telephone Order (MOTO).

  1. Go to the customer overview and activate a customer. By clicking on "Create Order" a new window opens up for the creation of the order
  2. Click on "Edit" and select the item and the options
  3. In the field payment method you can select the preferred payment method and click on "Submit Order"
  4. Depending on the authorisation method that you have saved for the selected payment method, you will either be redirected to the Payment Page of Computop or the mask for the credit card will appear such as in the image below. Enter the credit card data of the customer

6.3.1Refunding Orders

In order to refund orders, open the transaction information (cf. above). There you will find information on the transaction. Further below you will find an input field in which you can enter the amount you wish to refund. By clicking on "refund", the refund request will be transmitted to Computop. You no longer need to log into the back-end of Computop.

Figure 6.1: refund button

6.4Capturing / Cancelling of Orders

Please note

The transaction management between your shop and Computop is not synchronised. If you capture payments with Computop, the status in the shop will not be updated and a second capturing in the shop is not possible.

6.4.1Capturing / Cancelling of Orders

In order to capture orders, open the transaction information (cf. above). There you will find information on the transaction. Further below you will find an input field in which you can enter the amount you wish to capture. By clicking on "capture", the capture will be transmitted to Computop. You no longer need to log into the back-end of Computop.

By clicking on "Cancel Transaction" you cancel the transaction and the reserved amount is immediately released on the card of your customer.

Figure 6.1: capture oder cancel button.

6.5Usage of the Alias Managers / Token Solution

With the Alias Manager, your customers can securely save their credit cards with Computop for later purchases. You can enable this by activating the option "Alias Manager" in the configuration of the Payment Method. The customer can then choose from his or her saved credit cards without having to re-enter all the details.

Figure 6.1: Alias Manager
Please pay attention!

The usage of the Alias Managers requires the activation of the correct option with Computop. To do so, please contact the support directly.

6.6Set-up a cron job to activate the timed operations

To activate the timed operations of the plugin (e.g. update service, deleting pending orders, etc.), please activate in a regular request to the file computopcw_cron.php. The regular call triggers the appropriate actions.

Here we suggest you use a Cron Engine like for example EasyCron. That way you can This allows you to open the file ( URL ) with an external service.

7Testing

Before switching from test to live mode it is important that you test the module extensively. You can find all relevant test credit card data under: http://www.sellxed.com/de/testen.

Testing

Do not forget to switch the operating mode from test to live after having successfully tested the module.

7.1Test Data

In the following section you can find the test data for the various payment methods:
Credit Card
Card number
5399999999999999
Expiry Date
12/2020
CVC
123
Mastercard
Card number
4900000000000003
Expiry Date
12/2020
CVC
123
Visa
Credit Card (Be2Bill)
Card number
5399999999999999
Expiry Date
12/2020
CVC
123
Mastercard
Card number
4900000000000003
Expiry Date
12/2020
CVC
123
Visa
PayU CEE
Card number
4355084355084358
Expiry Date
12/2020
CVC
000
Visa
Open Invoice
Procedure
Use any valid German address. The first two attempts are succesful. The third will fail.
BillPay
Company
Must be empty
Firstname
Paul
Lastname
Positiv
Street
Teststr. 4
Post Code
49084
City
Osnabrück
Phone
095198009
BillSAFE: Accepted
Test Data
http://developers.klarna.com/en/testing/invoice-and-account
Klarna
Customer ID
customer1
Company
Must be empty
Gender
FEMALE
Firstname
Julia
Lastname
Tester
Street
Aalener Str. 57
Post Code
73492
City
Rainau
Country
DE
Phone
07361889969
E-Mail
customerEmail@domain.com
Birtday
1987-10-25
Paymorrow: Accepted
Last Name
Wischnewski
First Name
Hans-Jürgen
Birtday
1973-12-27
Street
Müllerstraße 137
Postcode
13353
City
Berlin
Country
DE
Phone
03018425165
RatePay: B2C
Company Name
Imperium UG
Sales Tax Number
DE123456789
Last Name
Descartes
First Name
René
Birtday
1973-12-27
Street
Odeonplatz 1
Postcode
80539
City
München
Country
DE
Phone
08945687541
RatePay: B2B
Direct Debits
Direct
Last Name
Wischnewski
First Name
Hans-Jürgen
Birtday
1973-12-27
Street
Müllerstraße 137
Postcode
13353
City
Berlin
Country
DE
Phone
03018425165
RatePay: B2C
Company Name
Imperium UG
Sales Tax Number
DE123456789
Last Name
Descartes
First Name
René
Birtday
1973-12-27
Street
Odeonplatz 1
Postcode
80539
City
München
Country
DE
Phone
08945687541
RatePay: B2B
BIC
BYLADEM1ROS
IBAN
DE36711500000009290701
InterCard: Accepted
Customer ID
customer1
Company
Must be empty
Gender
FEMALE
Firstname
Julia
Lastname
Tester
Street
Aalener Str. 57
Post Code
73492
City
Rainau
Country
DE
Phone
07361889969
E-Mail
customerEmail@domain.com
Birtday
1987-10-25
Paymorrow: Accepted

7.2Testing - Computop Simulation Mode

Any kind of payment method can be tested with our modules. The "Operation Mode" corresponds to the simulation mode with Computop. Payments with a total of less than 10'000 EUR are always accepted.

8Errors and their Solutions

You can find detailed information under http://www.sellxed.com/en/faq. Should you not be able to solve your problem with the provided information, please contact us directly under: http://www.sellxed.com/en/support

8.1Orders are not stored correcty, cart remains full

In case the shopping cart is not emptied after the customer returns from a successful payment, please check the following::

  • Make sure that you configured the backend of Computop every settings exactly as outlined above
  • Check that under Configuration > Sessions all the options are set to False.

8.2The Referrer URL appears in my Analytics Tool

When a customer and the notification are redirected via Header Redirection, the Computop Referrer URL might appear in your Analytics Tool thus hiding the original traffic source. However, most Analytic Tools are able to minimize this problem.

In case you are using Google Analytics as reporting tool, this step by step guide may help you to exclude the URLs: under bullet point 4.

9Error Logging

The module will log different unexpected errors or information depending on the configured level. If there is any issue with the module, this log can help identify the cause.

9.1Log Levels

You can configure the log level in the Computop settings.

  • Error: Logs unexpected errors only. (Default)
  • Info: Logs extended information.
  • Debug: Logs information helpful for debugging.

9.2Log Location

The log messages are visible in the xt:Commerce 3 backend under "Modules > XT-Modules > Computop Base Module > Log Messages".

10Advanced Information

This section of the manual is for advanced usage of the module. The content is for advanced users with special requirements. Everything in this section is optional and not required for the daily usage of the module.

10.1Transaction Object

This section describes how to extract information from a transaction, if you need it for further processing. E.g. You require more information of the transaction for further processing an order in your erp system.

The code snippets in this section assume your script resides in the root folder of the shop with the default shop folder structure.

Have xt:Commerce 3 initialized in your script, this is required for the database connection.
include ('includes/application_top.php');
Include the module main file and module classes.
require_once DIR_FS_DOCUMENT_ROOT.'admin/includes/ComputopCw/init.php';
require_once DIR_FS_DOCUMENT_ROOT.'admin/includes/ComputopCw/classes/ComputopCw/Entity/Util.php';
Now you can load the transaction and then extract the transactionObject.
Load the transaction by Id:
$transactionById = ComputopCw_Entity_Util::findTransactionByTransactionId($transactionId);
$transactionObject = $transactionById->getTransactionObject();
Load the transaction by external Id:
$transactionById = ComputopCw_Entity_Util::findTransactionEntityByTransactionExternalId($externalId);
$transactionObject = $transactionById->getTransactionObject();
Load transactions by Order ID:
$transactionsByOrderId = ComputopCw_Entity_Util::findTransactionsEntityByOrderId($orderId);
foreach($transactionsByOrderId as $transaction){
	$transactionObject = $transaction->getTransactionObject();
	//Do something with each object
}