A.5.5 response timeout, A.5.6 bus inactivity requirement, A.6 message structure – Comtech EF Data DT-4500-A Series User Manual
Page 115: A.6.1 start character, A.6.2 device address, A.6.3 command
DT-4500-A Series Downconverters
Revision 1
Appendix A
MN-DT4500A
A–5
A.5.5 Response Timeout
A minimum of 500 milliseconds is provided before declaring a “no response” instance, at which
time the command is re-transmitted.
A.5.6 Bus Inactivity Requirement
Comtech EF Data recommends that a minimum of 50 milliseconds bus inactivity be provided by
the user between the receipt of a response from an addressed converter and issuing the next
command on the serial bus.
A.6 Message Structure
The structure of a Command, Response, or Error Message is as follows:
•
Start Character
•
Device Address
•
Command or Response
•
End of Message String
A.6.1 Start Character
The Start Character begins each message:
Example:
< Start of a user Command.
> Start of a converter response.
A.6.2 Device Address
The Device Address consists of a Physical Address or a Physical Address and an appended Virtual
Address. This document uses DEV for the generic case examples.
Example:
<3V12
A.6.3 Command
A Command is a variable length character string beginning with a forward slash “/”’ and
containing either an instruction or an instruction and data for a converter to act upon. If data is
passed by command it is appended to the instruction by an underscore “_”. If data is retrieved
by command, underscore follows the instruction, flagging the converter to supply data in a
response.