Specifications
66 Rockwell Automation Publication AG-SG001G-EN-P - April 2015
Chapter 4 Choosing a Device for a Master Station
Choose the programmable controller based on processor memory requirements.
The following table provides a selection guideline for programmable controller-
based master stations. The guidelines are based on a maximum of 4 K of
programming memory for the polling master application logic and 200 words of
data table memory per remote station. Other application requirements might
dictate specifying a larger processor.
If an application requires multiple half-duplex master stations, you can use
multiple ControlLogix processors in a single 1756 I/O chassis, with each
processor supporting up to 254 remote stations. Using the built-in backplane to
serial port routing capability of the ControlLogix processor, any processor has
messaging capability to any remote station, no matter to which processor serial
port it is actually connected.
Choosing a Data-
concentrating Submaster
Station
If your application requires one or more data-concentrating serial submaster
stations, each submaster station must support both DF1 half-duplex master and
DF1 half-duplex slave communication through two serial ports. In this
application, the submaster can communicate directly with its master or its remote
stations, but any data exchange between its master and its remote stations can
only occur through the submaster’s data table. The master programming terminal
can remotely program the submaster, but not the submaster’s remote stations.
Alternatively, Ethernet can be used for communication to or from the submaster.
The MicroLogix 1400 controller can be configured as a serial submaster with
DF1 half-duplex slave on channel 0 and DF1 half-duplex master on channel 2, or
with DF1 radio modem configured on both channels. It has an Ethernet port for
communication as well.
If you have this number
of remote stations
Choose this processor or larger
1...10 •MicroLogix 1100 •CompactLogix L23E
11...50 •SLC 5/05 1747-L551
•CompactLogix L32E
•MicroLogix 1400
51...130 •SLC 5/05 1747-L552 •CompactLogix L35E
131...210 •CompactLogix L43
•ControlLogix
•SLC 5/05 1747-L553
211...254 •CompactLogix L45 •ControlLogix
> 254 Multiple ControlLogix