Touchpoint 4 Serial Communication Protocol Issue 1 09/07
Protocol Command Definition
Handshake command – 0x40
This is used to test for communication between the master and the specified slave.
Command packet to instrument:
Command code:
0x40
Data field:
null
Checksum:
1 byte
Example
:
If the master wants to test the communication with the addressed 01 instrument, it
should send out:
0x7f 0x01 0x01 0x40 0x3f.
Response packet from instrument:
Command code:
0x40
ACK code:
0x01
Checksum:
1 byte
Example:
The addressed 01 instrument receives the handshake command and responses:
0x7f 0x01 0x02 0x40 0x01 0x3d .
Get unit and points status - 0x30
This command requests the instrument date, time, alarm status, fault status and up-to-
four channel(s) status.
Command packet to instrument:
Command code:
0x30
Data field:
null
Checksum:
1 byte
Example:
0x7f 0x01 0x01 0x30 0x4f means the master requests the status of the
instrument whose address is 1.
Response packet from instrument:
Command code:
0x30
Date field:
Date:
2 bytes
Time:
2 bytes
Unit alarm status:
1 byte
0x00: no alarm
0x01: A1 alarm
0x02: A2 alarm
0x03: A1 and A2 alarm
8