I will be trialing a few of the Temco Bacnet/Modbus controllers and programmable thermostats for commercial HVAC applications. Tstats8’s may be used for Fancoil and VAV Box Control and Monitoring over Bacnet MS/TP. The T3-XB’s with T3-IO’s may reside on TCP/IP Ethernet Networks, for AHU Control, Monitoring and Trending of (All) connected Analog Inputs.
My typical (Standard) RS485 bus topology supports 32 (Daisy Chained) devices between “EIA-485 Repeaters” on a single bus of approximately 1200 meters length with 18 AWG twisted shielded cable, 3 repeaters increase the total to 128 devices with a maximum RS485 bus length of approximately 2800 meters (3 repeaters with four segments).
My questions are;
- What is the recommended topology for Temco Tstat7’s, Tstat8’s, Tstat9’s, Tstat10’s to T3-XB, T3-Nano or USB-RS485 Gateways/ Controllers/Converters
- Are separate end of line termination resistors (EOL, 120 Ohm, 1/4, watt 5%) required on the 485 Bus.
- What are the recommended maximum quantity of Tstat8’s per T3-XB’s and T3-Nano’s.
- What are the maximum quantity of T3-XB’s, T3-IO’s and T3-Nano’s per each Ethernet Bus
I would like to create a similar wiring topology diagram (for my use), but have not seen / found any info on “Quantity of devices” in the Temco Controls Documentation. Thanks.