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CS1W-SRM21 Master Unit for CS-series PLCs
Section 4-2
Part Names and Functions
Indicators
The following table shows the meaning of the indicators.
Indicator
Status
Meaning
RUN (green)
ON
The Unit is operating normally.
OFF
Indicates one of the following conditions (the ERH and
ERC indicators light when errors other than the following
errors occur):
Power is not turned ON, watchdog timer error, etc.
ERH (red)
ON
Indicates one of the following conditions:
Errors occurring at the CPU Unit, such as Special I/O Unit
number setting error.
OFF
The Unit is exchanging data with the CPU Unit normally.
ERC (red)
ON
Indicates one of the following conditions:
Master Unit internal error, communications error, or verifi-
cation error
OFF
The Slaves are communicating normally.
SD (yellow)
ON
Data is being transmitted.
OFF
Data is not being transmitted.
RD (yellow)
ON
Data is being received.
OFF
Data is not being received.
Indicators
Indicates the operating status of the Master Unit
and the status of communications with the Slaves.
Rotary Switches
Used to set the Master Unit’s Special I/O Unit
number at the CPU Unit as a 2-digit decimal
number. The top switch is used to set the ten’s digit
and the bottom switch is used to set the one’s digit.
DIP Switch
These pins have the following functions:
Pin 1: Usable node number setting
Pin 2: Communications mode
Pin 3: Communications stop mode
Pin 4: Slave registration function
Communications Connector
Used to connect the Slave’s communications power
supply and communications cables. When the
communications power supply is not supplied to the
Slaves from communications cable, connect the
communications cable BD H and BD L signal lines
only.
