Comtech EF Data CDM-760, Installation And Operation Manual

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Serial Interface Operation Revision 3
CDM-760 Advanced High-Speed Trunking Modem MN-CDM760
8–5
8.4.2.4 Instruction Code
This is a three-character alphanumeric sequence that identifies the message subject. Uppercase alphabetic characters (‘ A ’ to ‘ Z ’, ASCII Codes 65
to 90) and the numbers ‘ 0 ’ to ‘ 9 ’ *ASCII Codes 48 to 57) may be used. Wherever possible, each instruction code is named to serve as a
mnemonic for its intended operation. This helps you interpret the code function, should it be shown in its raw ASCII form.
For example: TFQ stands for Transmit Frequency, RMD for Receive Modulation Type, etc.
8.4.2.5 Instruction Code Qualifier
This is a single character that further qualifies the preceding instruction code.
8.4.2.5.1 Controller-to-Target Instruction Code Qualifiers
The only permitted characters are ‘=’ and ‘?’.
=(ASCII Code 61)
This character is used as the Assignment Operator (AO). It establishes that the Instruction Code that precedes it is issued as a command to assign
or configure operation. The instruction set that follows serves to assign the Target’s new parameter setting or operational value.
For example: From Controller-to-Target, <0/TFQ=0070.0000 means “set the Transmit frequency to 70 MHz.”
? (ASCII Code 63)
This character is used as the Query Operator (QO). It establishes that the Instruction Code that precedes it is issued as a query that returns the
Target’s current configured parameter setting or operational value.
For example: From Controller-to-Target, <0/TFQ? means “what is the current value of the transmit frequency?”.
8.4.2.5.2 Target-to-Controller Instruction Code Qualifiers
The permitted characters are ‘=’, ‘?’, ‘*’ , ‘!’, ‘*’, ‘#’, and ‘~’.
=(ASCII Code 61)
This character is used in two ways: