Rev. 2 | |
Serial Remote Control | CD/CIM550.IOM |
2)From Target to Controller, the only permitted values are:
=(ASCII code 61)
?(ASCII code 63) ! (ASCII code 33) * (ASCII code 42)
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.
Second, if the controller sends an instruction to set a parameter to a particular value, then, providing the value sent in the argument is valid, the target will acknowledge the message by replying with TFQ= (with no message arguments).
The ? code (target to controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then, if the value sent in the argument is not valid, the target will acknowledge the message by replying (for example) with TFQ? (with no message arguments). This indicates that there was an error in the message sent by the controller.
The * code (target to controller) is only used as follows:
If the controller sends an instruction to set a parameter to a particular value, then, if the value sent in the argument is valid, BUT the modem will not permit that particular parameter to be changed at that time, the target will acknowledge the message by replying (for example) with TFQ* (with no message arguments).
The ! code (target to controller) is only used as follows:
If the controller sends an instruction code which the target does not recognize, the target will acknowledge the message by echoing the invalid instruction, followed by the ! character with. Example: XYZ!
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