Specifications

67
Schneider Electric
The Modbus Protocol (continued)
Read diagnostic counters: function 8
b Query/response.
(1) For the query XXXX equals 00 00.
For the response, xxxx is the contents of the counter.
Each slave has a number of event counters
(or diagnostic counters):
b There are a total of 9 counters per slave.
b These counters are 16-bit words.
E52489
1 byte 1 byte 2 bytes 1 byte
Slave No.
8
CRC 16
Sub-function
code
Data
2 bytes
Function Sub-function code Data Notes:
The slave should echo the query
(transmission control).
00 XYZT X, Y, Z, T set by
the user
Reset diagnostic counters to zero,
cancel disconnected mode and
reconfigure coupler. No response
transmitted.
01 0000
Diagnostic counters and trace buffer
reset to zero.
01 FF00
Read diagnostic register of slave. 02 XXXX For the query
XXXX equals
0000.
For the response
XXXX is the
contents of the
diagnostic
register (set by
the user).
Change character that serves as a
frame end delimiter (in ASCII
mode). This character is LF (OA) by
default.
03 XY00 XY set by the
user: ASCII code
of the end-of-
frame character.
Disconnected mode – the slave can
no longer respond. (Use sub-
function 1 to activate slave.)
04 0000
Reset diagnostic counters to zero 0A 0000
Read total number of:
v frames received without CRC
error (CPT 1)
0B XXXX
(1)
v frames received with CRC error
(CPT 2)
0 C XXXX
(1)
v number of exception responses
(CPT 3)
0 D XXXX
(1)
v frames addressed to the station
(CPT 4) (except broadcast)
0 E XXXX
(1)
v broadcast queries received
(CPT 5)
0 F XXXX
(1)
v nacknowledged responses
(CPT 6)
10 XXXX
(1)
v not ready responses from the
slave (CPT 7)
11 XXXX
(1)
v unprocessed characters (CPT 8) 12 XXXX
(1)
Guide to Integration
Modbus / Jbus