For the following explanation please compare the Installation Instructions (attached):
1) Please connect the RS485 terminals of RTD-10 interfaces as shown in figure 4 (see the installation instructions): DB to DB, DA to DA, and GND to GND.
- If a RTD-RA is to be added to the network (the case when indoor unit only compatible to RTD-RA) then connect the RS485 terminals of RTD-RA interface(s) as shown in figure 3 (see the installation instructions): DB to DB, DA to DA, and GND to GND.
2) Please set the DIP switches of the RTD-10 interfaces as described in the article Duty/Standby DIP Switch Settings.
- Up to 8 RTD-10 interfaces (1 master + 1 slave) can be networked together for Duty/Standby operation.
- Up to 16 indoor units can be networked (as a group) to one RTD-10 interface via the P1P2 network.
- If more than 8 RTD-10 interfaces are to be operated in Duty/Standby mode then a second Duty/Standby network will need to be installed. Both networks will operate independently of each other. If independent networks are not wanted then a custom solution must be implemented with your PLC/BMS (see FAQs).
- Only RTD-10 interfaces set to Duty/Standby operation can be placed on the same RS485 network. If RTD-10 interfaces in Duty/Standby operation mode and another RTD-10 operation mode are to be wired on a RS485 network then a Modbus gateway is required (see the article RTD-DSX: Our Modbus gateway for further details).
If a RTD-RA is added to the Duty/Standby network:
- Please set the DIP switches as described in this article.
3) Wire only the inputs (S1 - S6) of the Master RTD-10 (RS485 address = '0') for setting setpoint, fan speed, rotation, etc.
- If an input is not wired (open circuit) then the RTD-10 default values are applied (bold and underlined values in the installation instructions - table on page 11).
- The rotation cannot be scheduled to specific times. It can only be set as described in the RTD-10 installation instructions.
4) Wired remote controllers can be wired to each RTD-10. However, parameters can only be set from the wired controller which is connected to the master RTD-10 (RS485 address = '0').
- Please configure the wired controller as SUB P1P2 device (see this article for instructions).
- Note that: If S1 and S2 are wired then setpoint and fanspeed are set by the RTD-10 inputs (S1 and S2) and the corresponding buttons on the remote controller are locked. If S1 and S2 are not wired then the buttons on the master remote controller are unlocked and can be used to set operating values. In this mode the setpoint is limited to the range 20 to 32°C.
- Parameters are only set through the master RTD-10 (applies for S - inputs and RemCon)
5) If you want to use an auxiliary thermistor for monitoring then wire a 10k thermistor on S4 input (details in installation instructions - page 13 and the article RTD-10: Auxiliary Thermistor)
- Note that the auxiliary thermistor is only for monitoring and alarm signalling (level1 and level 2 alarms - see installation instructions).
- In Duty/Standby mode it is not possible to use the remote controller's thermistor for alarm monitoring.
6) Wire the RTD-10 relays (master and slave RTD-10 relays close on alarm signals) if required. Note that that relays are Voltage-free contacts (dry contacts). Please make sure the power ratings of the relays are not exceeded (see installation instructions - page 6)
- The Master RTD will report Level 1 and Level 2 alarms for any RTD in the group.
- The Slave RTD will only report alarms for its local AC unit.
7) Modbus: In Duty/Standby mode the RTD-10 Duty/Standby master interface (RS485 address = '0') is the Modbus master. Therefore, no other Modbus master can be placed on the Modbus network. A Modbus gateway must be placed on the network to access with Modbus the RTD-10 interfaces operating in Duty/Standby mode. We recommend our RTD-DSX interface as Modbus gateway. Read the article 'RTD-DSX: Our Modbus gateway' for further information.
Can the relay signals be changed?
Yes. They can be changed as described in these instructions (click here).
Testing the installation
- You can confirm that Duty/Standby configuration is correct by testing the All On and All Off functions by applying a link to S5 and then S6.
- For testing the rotation place a 0 ohm link on S3 which will cause the system to operate in test mode with a 60 second rotation time. The system should only be operated in test mode for short time periods.
- You can generate an indoor unit fault by pulling out a sensor.
- Note: Disconnecting the RS485 links when the RTD-10 interfaces are in Duty/Standby operation will not generate a fault signal
- If you want to test each RTD on it's own first (e.g. to make sure communication with indoor unit is correct):
- Configure each RTD-10 for standard Resistance mode control (all DIP switches OFF). Then you can test the control function using input S5 to switch the unit on and off. Please refer to the RTD-10 installation manual for details.
- In Standard operation mode testing can be performed via hardwired inputs, as well as Modbus. It can be tested without connecting an indoor unit. For information on testing via Modbus, please follow this link.
- After this, configure the RTD-10s for Duty-Standby and perform the Duty/Standby tests as described above.
- Configure each RTD-10 for standard Resistance mode control (all DIP switches OFF). Then you can test the control function using input S5 to switch the unit on and off. Please refer to the RTD-10 installation manual for details.