Premier Mounts CDM-600 specifications Instruction Code Qualifier

CDM-600 Satellite Modem	Revision 7
Remote Control	MN/CDM600.IOM

16.5.3Instruction Code

This is a three-character alphabetic sequence that identifies the subject of the message. Wherever possible, the instruction codes have been chosen to have some significance. For example TFQ for transmit frequency, RMD for receive modulation type, etc. This aids in the readability of the message, should it be displayed in its raw ASCII form. Only upper case alphabetic characters may be used (A-Z, ASCII codes 65 - 90).

16.5.4Instruction Code Qualifier

This is a single character that further qualifies the preceding instruction code.

Code Qualifiers obey the following rules:

1)From Controller to Target, the only permitted values are: = (ASCII code 61)

?(ASCII code 63) They have these meanings:

The ‘=’ code (controller to target) is used as the assignment operator, and is used to indicate that the parameter defined by the preceding byte should be set to the value of the argument(s) which follow it.

For example, in a message from controller to target, TFQ=070.0000 would mean ‘set the transmit frequency to 70 MHz’

The ‘?’ code (controller to target) is used as the query operator, and is used to indicate that the target should return the current value of the parameter defined by the preceding byte.

For example, in a message from controller to target, TFQ? would mean ‘return the current value of the transmit frequency’

2)From Target to Controller, the only permitted values are: = (ASCII code 61)

?(ASCII code 63) ! (ASCII code 33) * (ASCII code 42)

# (ASCII code 35) ~ (ASCII Code 126)

They have these meanings:

The ‘=’ code (target to controller) is used in two ways:

First, if the controller has sent a query code to a target (for example TFQ?, meaning ‘what’s the Transmit frequency?’), the target would respond with TFQ=xxx.xxxx, where xxx.xxxx represents the frequency in question.

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