Residential Control Systems TR16, Инструкция по установке и эксплуатации

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DCN: 141-00930-07 09/06/04 12
Serial Communications
Serial Communications
The TR16 Control Unit has a RS485 serial communications port. RS485 communications is two wire, half
duplex. Commands from remote systems can change the setpoint temperatures and mode of the
Thermostat. The Control Unit connects to the serial wiring via a 4 wire connector (with optional 12VDC
power). Serial commands received by the Control Unit can set a new setpoint or a new mode and are sent to
the WDU to update its display. When serial commands that update the setpoint or mode are received, the
WDU will switch it’s display to show the updated information for three seconds and then return to the current
temperature display.
TR16 Thermostats also responds to request for status by serial commands and can provide all thermostat
data and setup information as well as the current revisions of the WDU and Controller firmware.
Address Setting
The TR16 serial communications address is set from the Wall Display Unit by entering the setup mode. To
enter the setup mode, press and hold the Mode button and simultaneously press the Fan button. This enters
the setup mode and “Ad” will be displayed. Set the desired address by pressing the UP/DOWN buttons until
the desired address from 1 to 99 is selected. The default address is 1.
Serial Protocol
The TR16 thermostat has a robust serial protocol. It is based on a simple ASCII message format as
described in the RCS Serial Communications Protocol manual, DCN# 150-00225.
Note: NOT ALL of the commands/variables defined in the protocol document are applicable to the TR16,
check Section 8 of the protocol manual for details.
The following thermostat information can be sent to or requested from the thermostat by the serial protocol.
•
Temperature
•
Heating setpoint
•
Cooling setpoint
•
System Mode
•
Fan Mode
•
F/C mode
•
HVAC output status
•
Network Address
•
Any system variable
•
System firmware revisions
Serial Communications Setup
To communicate to TR16 thermostats, set the communications parameters of the host system to: 9600
baud, no parity, 8 bits, 1 stop bit and No flow control.
Transmission delay . The TR16 will delay responses to request messages for 5mS to conform to the RCS
CommStar network protocol. This is necessary for RS485 half duplex devices to use Send Data Control for
automatic flow control.