Procedures
MVI56E-MNETC ♦ ControlLogix Platform
Setup Guide
Modbus TCP/IP Multi Client Enhanced Communication Module
Page 58 of 72
ProSoft Technology, Inc.
April 18, 2011
4.11.2 Checking Module Status through ControlLogix Controller Tags
You can view network status through the ControlLogix controller tags that are
updated through the MVI56E-MNETC sample ladder.
To verify that the Modbus TCP/IP Client is communicating with one or more
Modbus TCP/IP Servers, view the contents of the two ReadData array elements
beginning at the address you used for the
C
OMMAND
E
RROR
P
OINTER
parameter,
minus the value of the
R
EAD
R
EGISTER
S
TART
parameter.
In this case, the
C
OMMAND
E
RROR
P
OINTER
was set to 1500 and the
R
EAD
R
EGISTER
S
TART
to 1000. This means that (1500 – 1000 = 500); so
R
EAD
D
ATA
[500]
and
R
EAD
D
ATA
[501]
will tell you the individual status of each of
the two commands issued by the module.
To verify that the Modbus TCP/IP Server is communicating with a Modbus
TCP/IP Client, view the contents of the
MNETC.STATUS.C
LIENT
S
TATUS
[0]
tag
for total commands issued, responses received, errors, and so on.
The following controller tags should increment periodically, indicating that the
Modbus TCP/IP Client is continuously sending commands and receiving
responses:
MNETC.STATUS.C
LIENT
S
TATUS
[0].C
MD
R
EQ
MNETC.STATUS.C
LIENT
S
TATUS
[0].C
MD
R
ESP
MNETC.STATUS.C
LIENT
S
TATUS
[0].R
EQUESTS
MNETC.STATUS.C
LIENT
S
TATUS
[0].R
ESPONSES
