Instruction Code Qualifier - Comtech EF Data CDM-800 Installation And Operation Manual

CDM-800 Gateway Router
Serial-based Remote Product Management
6.2.2.5

Instruction Code Qualifier

This is a single character that further qualifies the preceding instruction code. Code Qualifiers obey the following rules:
From Controller‐to‐Target, the only permitted characters are:
Character
=
(ASCII code 61)
?
(ASCII code 63)
From Target‐to‐Controller, the only permitted characters are:
Character
=
(ASCII code 61)
?
(ASCII code 63)
Definition
This character is used as the Assignment Operator (AO). It establishes that the Instruction Code that precedes it is to
be used 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.
Example: In a message from Controller-to-Target, IG1=aaa.bbb.ccc.ddd/yy means "set the GE Port IP address to
aaa.bbb.ccc.ddd/yy"
This character is used as the Query Operator (QO). It establishes that the Instruction Code that precedes it is to be used
as a query that returns the Target's current configured parameter setting or operational value.
Example: From Controller-to-Target, IG1? means "what's the current GE Port IP address?"
Definition
This character is used in two ways:
a. If the Controller sends a query to the Target – for example, CMD? (meaning "what's current value of this parameter?")
– the Target responds with CMD=xxx, the value for that queried parameter.
b. If the Controller sends an instruction to set a parameter to a particular value, and the value sent is valid, the Target
acknowledges the message and responds with CMD= (with no message arguments).
If the Controller sends an instruction to set a parameter to a particular value, and the value sent is not valid, the Target then
acknowledges the message and responds with, for example, CMD? (with no message arguments). This indicates that there
was an error in the message sent by the Controller.
6–6
Revision 1
MN-CDM800