CIPer
TM
MODEL 50 CONTROLLER
–
INSTALLATION AND COMMISSIONING INSTRUCTIONS
21
31-00233-02
Modbus Connection
The CIPer Model 50 controller can function as a Modbus Master or Slave. In general, the RS485 wiring rules
must be followed.
Wiring Topology
Only daisy-chain wiring topology is allowed.
Figure 19: Allowed Modbus wiring topology
Other wiring topologies (e.g., star wiring, or mixed star wiring and daisy chain wiring) are prohibited; this is to
avoid communication problems of the physical layer.
Figure 20: Prohibited Modbus wiring topology (example)
Cables
See also section "EIA 485 Cable Specifications".
Use shielded twisted pair cable 3322 or 3251.
You must use three wires:
•
One wire for D1 =
•
One wire for D0 = Modbus
–
•
One wire for the signal common
When using one pair for D1 and D0 and one wire of another pair for the signal common, CAT5 cable may also
be used.
For connection details, see section "Modbus Connection" .
MODBUS
MASTER
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
MASTER
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
MODBUS
SLAVE
X
X