Moore Industries NET Concentrator System AOM, Руководство пользователя

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NET Concentrator System
®
NCS
- 46 -
Moore Industries-International, Inc.
www.miinet.com
Viewing Peer-to-Peer Faults
via MODBUS
The Peer-to-Peer Status Register can be accessed
via MODBUS/TCP or by MODBUS RTU. A MODBUS
master on a Peer-to-Peer link may interrupt the
Peer-to-Peer communications on that link and poll
any slave for diagnostics, or any other data. When
the MODBUS Master goes silent, Peer-to-Peer
communications will resume. The 16-Bit “Peer-to-Peer
Status Register” may be read using MODBUS analog
commands 3 and 4. The individual flag bits within
the register are also available through discrete read
commands 1 and 2 where “B” is the bit position within
the Peer-to-Peer Status register (see table below).
The bit positions and corresponding faults are outlined
in P2P Table 1.
Diagnostics
Faults preventing correct process data from reaching
a consumer station, or “Peer-to-Peer faults”, will be
flagged and made available in the consumer station
for you to access via MODBUS, the web pages, or the
NCS PC Configuration Software program. In addition,
the Status LED of the consumer station will turn red.
Refer to P2P Table 1 for descriptions of these faults
and their causes.
Loss of Port 1 on a Redundant
Peer-to-Peer System
When the communication link to Port 1 is severed,
Peer-to-Peer communications will automatically switch
to Port 2, the redundant port. When this happens, the
status LED on the consumer(s) will turn red and the
appropriate MODBUS status bits in Appendix B Table
17 will be activated to true. This Port 1 communication
failure can also be seen when using the NCS
Configuration Software in the “Monitor Process Data”
view. Once the severed link for Port 1 has been
repaired, the Peer-to-Peer communication link will
switch back to Port 1 and the LED will return to green
with the status bits resetting back to false.
Note:
Peer-to-Peer will automatically switch to Port 2 ONLY
when Port 2 is configured for Peer-to-Peer AND the
RS-485 bus is healthy.
Display of Peer-to-Peer Faults in
NCS PC Configuration Software
Program
Peer-to-Peer faults on a given station can be viewed
through the PC Configuration Software program on the
Process Data page of the consumer station, the same
page where system level faults are listed. Descriptions
of all present faults are shown simultaneously.
Variable
Peer-to-Peer
Status Register
Peer-to-Peer
Status Flags
Register Address
4009 (Analog Commands)
4129 + B (Discrete Commands)
Fault Conditions
If any of the faults listed in P2P Table 1 are present,
meaning data is not available to drive the output, the
output channel behaves according to the “Output
On Failure” parameter(s) in the output channel
configuration. See P2P Figure 5 for an example of
output channel configuration.
P2P Table 1.
MODBUS Peer-to-Peer Faults
Input/Output Modules for NET Concentrator System