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Avoiding Escaping Delimiter Characters For a Field

Some HL7 messages may contain special delimiter characters such as ^ or ~. For each delimiter character, HL7 has a system for escaping them (see Delimiter Escape Sequences).

However, in certain cases you may be required to not escape delimiter characters for a field. For example, let's assume that you need to send multiple fields from an OBX segment to another application. The application requires the OBX.5 field to contain a ~ character for each new line. If you did not avoid escaping the ~ for the OBX field, your line would start with \R\ (HL7 escape sequence) instead of ~ . Fortunately, you can use Python to easily replace any escaped characters for an outbound value of a field from an HL7 message.

	This example shows you how to replace the \R\ sequence with the ~ in the OBX.5 field. To replace other characters, the escape sequences will be similar (see Delimiter Escape Sequences for details).

To use Python to replace escaped characters:

• Open your VMD file in Chameleon.
• In the Workspace, double-click the segment you want to replace escaped characters for (e.g. OBX segment). The Segment - OBX window appears as shown below.

Segment Window - OBX Segment

• In the Segment - OBX window, click the Outbound Script ellipsis button for the field you want to modify. The Editing Script window appears.
• In the Editing Script window, type the following as shown below:

Editing Script Window

• Click OK to confirm your change.

This line of code replaces all new OBX.5 lines so that they contain a ~ instead of \R\ at the beginning of each new line.