6.8.3 Diagnostic Command
This command echoes the sent message to indicate that the communication link is
established correctly.
SEND TO/RETURN FROM DEVICE:
DEVICE FUNCTION DIAGNOSTIC LOOPBACK CRC
ADDRESS CODE CODE DATA
1 BYTE 1 BYTE HB LB HB LB LB HB
nn 08 00 00 nn nn nn nn
Where: Diagnostic Code is two byte code to determine the type of test to be performed.
i-Series devices supported only “00” code which requested slave to echo sent command
back to the master.
Example:
SEND TO DEVICE: Address 01, Diagnostic command (08), data value 8755 Dec
(2233 Hex)
DEVICE FUNCTION DIAGNOSTIC LOOPBACK CRC
ADDRESS CODE CODE DATA
01 08 22 33 00 00 BE B8
RETURNED FROM DEVICE:
DEVICE FUNCTION DIAGNOSTIC LOOPBACK/ CRC
ADDRESS CODE CODE DATA
01 08 22 33 00 00 BE B8
6.8.4 Error Response
When a device can not properly respond to the command due to incorrect or corrupted
command, it will respond with an error message. The error massage has the following
format:
DEVICE FUNCTION ERROR CRC
ADDRESS CODE RESPONSE
1 BYTE 1 BYTE 1 BYTE LB HB
nn nn nn nn nn
i-Series devices support the following error code messages:
02 – read from/write to the illegal register – read from/write to the register, which is
inactive, or not supported by i-Series devices
03 – write an illegal value – write out of range value
4141
To Next Page
Loading...
Need help?
General
