Bitzer CM-RC-01, Reference Manual

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v. 3.0 Reference guide
Compressor Control Module CM-RC-01
3.0
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5.2 Enable serial control
The serial control is inactive by default.
To enable the serial control set the parameter to 1 (COM1 Modbus).
To disable serial control:
Set parameter “Serial Control Source” to 0 (= None).
5.3 Required signals to start the compressor
Min. signals required to start the compressor via the CM-RC-01
5.3.1 Digital and analogue signals
Serial Control Source = 0 (None)
Start command
CN2:Relay C Setpoint
CN13:Cap. Input Compressor
State
– –
Stopped
Off
–
Stopped
On 0
– 100%
Running
Note: Please observe max number of starts per hour
5.3.2 Serial control (Modbus)
Serial Control Source = 1 (Modbus)
Start command
Control Word Setpoint
Serial Setpoint Compressor
state
– –
Stopped
Off
–
Stopped
On ±100 % Running
Note: Please observe max number of starts per hour
Control commands can be given to the CM-RC-01 via the Serial Control Word. The bit definitions
are shown in the table below.
The protocol used is Modbus (RTU). Modbus register definitions are listed in section 10.3
Parameters.
5.4 Control Word bit definitions
Bit Function Description
0-2 Reserved Must be set to 1
3 Operation enable Enable operation (0=off, 1 = enabled)
4 Reserved Must be set to 1
5 Reserved Must be set to 1
6 Start Start command is active when bit = 1
7 Reset Reset alarm command is active when bit is set from 0 to 1.
Positive edge triggered.
8-9 Reserved
10 Data valid Instruct controller to accept control word. Otherwise all other
bits are ignored.
The resulting control word will always have this set.
Please see section 10.3.1 Control
– application
11-15 Reserved
The data valid bit must be set to update the serial control word and the serial setpoint.