Moore Industries NET Concentrator System AOM, Руководство пользователя

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NET Concentrator System
®
NCS
- 40 -
Moore Industries-International, Inc.
www.miinet.com
Hardware Configuration
Peer-to-Peer mode transfers data from an input
module to an output module of the correct type (i.e.,
analog or discrete) in the same position. For example,
if the Producer station has a NCS-TIM-AIM-DIM
configuration, then the consumer station must have a
NCS-AOM-AOM-ROM configuration. If the discrete
and analog module positions are not the same in the
producer and consumer, the consumer will report an
incompatible module fault (see P2P Table 1).
Failover
In a consumer station, if both ports are configured for
Peer-to-Peer Mode, the outputs will be driven by the
inputs from the port 1 producer. If for any reason, that
producer is no longer available, the consumer will “fail
over” to port 2, and will begin to use the data from the
port 2 producer.
The failover mechanism is distinct from an input
failure. In the case of a sensor, input channel, or input
module failure, the corresponding output(s) will be
driven to their programmed fail response or output-on-
failure setting. The rest of the station will continue to
consume data from the producer on port 1.
Network Redundancy
It is possible to achieve network redundancy simply by
using Peer-to-Peer on both ports of all NCS modules,
and providing separate physical network connections
for each port. This will protect against network
problems, but not a problem with a producer.
Producer Redundancy
Configuring the NCS such that the port 2 producer is
different from the port 1 producer will protect against
failure of the port 1 producer. If something happens
to the port 1 producer, the failover mechanism will
cause data to be consumed from the still intact port 2
producer. This can be done with everything on a single
network, or with separate networks to also provide
network redundancy.
MODBUS RTU Peer-to-Peer
Systems
In addition to master and slave modes, the RS-485
ports on NCS Interface Modules can be configured
for Peer-to-Peer Mode. In this mode, the inputs on a
(producer) station are automatically transferred to the
outputs on one or more (consumer) stations. Input
failures and network disruptions cause the output to
be driven with their programmed fail response (hold
last or go to a preset value.)
Note:
For Peer-to-Peer mode each EMM in the system can
be connected to a maximum of 6 I/O modules.
Pee r-to-Peer mode may be used on a single port,
leaving the other free for operation in Master or Slave
mode. Using both ports for Peer-to-Peer allows a
failover mechanism to be used which provides for
producer and/or network redundancy.
Producer and Consumer
In a Peer-to-Peer System, a station can be a producer,
a consumer, or both.
- Producer: The station has one or more Input
Modules, it “produces” data for other stations on the
network to use.
- Consumer: The station has one or more Output
Modules, it “consumes” data from other stations on the
network.
- Producer and Consumer: The station has a
mixture of Input and Output Modules. The inputs are
producing data for other stations, and the outputs are
consuming data from another station.
For example, if an NCS-AIM system is connected via
a Peer-to-Peer Network to a NCS-AOM, the NCS-AIM
system will be a producer and the NCS-AOM System
will be a consumer.
Note:
When configuring a Peer-to-Peer Network, all stations
must be configured with the same mode and bus
properties (i.e., baud rate and character format.) Refer
to the Peer-to-Peer Software Configuration section for
more information.