Modbus Connection; Modbus Considerations; Connecting Ciper Model 50 Via Rs485-1 Interface To A Modbus - Honeywell CIPer 50 Installation & Commissioning Instructions

CIPer MODEL 50 CONTROLLER – INSTALLATION AND COMMISSIONING INSTRUCTIONS
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Modbus Connection

The CIPer Model 50 controller supports both Modbus RTU master and Modbus RTU slave functionality.
Modbus slaves can be connected to either or both of the two onboard RS485 interfaces: RS485-1
(consisting of push-in terminals 24 [GND-1], 25, and 26) or RS485-2 (consisting of push-in terminals 29,
30, 31 [GND-2]).
NOTE
GND-2 is internally connected with 24V-0 (terminal 1)

Modbus Considerations

• RS485-1 (isolated)
– Max. Modbus length: 3600 feet (9.6 – 78.8 kbps) or 2400 feet (115.2 kbps) (see also section "RS485
Standard" ).
– Use only shielded, twisted-pair cable and daisy-chain topology.
– Must conform to EIA-RS485 cabling guidelines (see section "EIA 485 Cable Specifications").
• RS485-2 (non-isolated)
– Max. Modbus length: 3600 feet (9.6 – 78.8 kbps) or 2400 feet (115.2 kbps) (see also section "RS485
Standard" ).
– Use only shielded, twisted-pair cable and daisy-chain topology.
– Ground noise should not exceed the EIA-485 common mode voltage limit.
– Must conform to EIA-RS485 cabling guidelines (see section "EIA 485 Cable Specifications" ).
– Should not extend beyond a single building.
• Max. no of Modbus devices per CIPer Model 50 RS485 interface: 32 (including the CIPer Model 50,
itself, which is counted twice)

Connecting CIPer Model 50 via RS485-1 Interface to a Modbus

With regards to
Figure 50: Connection of an CIPer Model 50 Modbus master controller via its RS485-1 interface to a
Modbus with slaves
, please note the following:
NOTE
• Always power each CIPer Model 50 controller and the connected BACnet MS/TP modules
via separate transformers.
• For "L," see section "RS485 Standard".
• If any of the devices are electrically isolated, it is recommended that those devices be
connected to signal ground. See section "RS485 Standard"
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