Status Request
Note: The Status Request should only be used when the train is stationary. Sending this command
simultaneous to tags being read can create a condition whereby the interrogator will no longer
report tags until power cycled.
The Status Request command causes the interrogator to respond with a message containing information
indicating the transponder seen count and host error messages.
The request command format is as follows:
<7EH><7EH><40H><CRC>
The response is
<7EH><7EH><02H><Transponder count><host
computer messages-bad CRC><incomplete host message>
<Reserved><Reserved><Reserved><CRC>
Table 3 Status Request Message Fields
Field
Description
Hex
ASCII
Start of Message
These two bytes designate the start of the data
message.
7E7E
~~
Message Type
Sending a 40H indicates that this message is a
status request.
40
@
Cyclical Redundancy
Check
The 8-bit cyclical redundancy check (CRC)
includes the Start of Message and Message Type.
See
of the CRC algorithm. This is a fixed value of
40 hexadecimal, for this command. There is no
carriage return or line feed for this message.
40
@
Chapter 6 Commands
TransCore Proprietary
6–23
