Module

Description

GetField()

• takes two parameters:

  • a string containing a message

  • an integer containing a field number

• If the field number is valid (in the range 1 to 3, inclusive), it returns a string containing the required field, otherwise it returns an empty string.

Field number

Field name

Description

Not applicable

STX

a single character marking the start of the message (ASCII value 02)

1

DestinationID

three numeric characters that identify the destination computer

2

SourceID

three numeric characters that identify the source computer

3

Data

a variable length string containing the data being sent (Minimum length is 1 character)

Not applicable

ETX

a single character marking the end of the message (ASCII value 03)