Microprocessor Controller for DOAS
39
Baud Rate Setting
In order for the space thermostat to communicate with the microprocessor, the correct baud rate must be set in the
space thermostat. To set the baud rate:
• The “PROG” DIP switch on the back of the space thermostat must be flipped to the right side.
• Use the Set Point Down button to display P11 on the space thermostat.
• Push the Scroll button and use the Set Point Up/Down buttons to adjust the baud rate to 192.
• Once 192 is displayed, push the Scroll button again to save the setting. Once the setting is saved, P11 should
appear on the display.
• Flip the “PROG” DIP switch on the back of the space thermostat back to the left. The space thermostat should
communicate and be set back to normal mode.
Space Thermostat Modbus Address
T-Stat 1 (Display)
T-Stat 2
T-Stat 3
T-Stat 4
Address in Microprocessor
10
11
12
13
Dip Switch Set on Stat
Sw 2 + Sw 8
Sw 1 + Sw 2 + Sw 8
Sw 4 + Sw 8
Sw 1 + Sw 4
Status LED
Green
indicates that the unit is operating properly.
Red
indicates that there is a problem with the unit.
Network LED
Flashing Red Slowly
indicates that there has been no communications for 60 seconds.
Flashing Green Slowly
indicates that there have been normal communications within
the last 60 seconds.
Flashing Green Slowly with Quick Red Flashes;
the quick red flashes indicate active
communications.
Terminal
Description
GND
Power Supply Ground (common to the controller)
Net B
RS485 network connection (Data - )
Net A
RS485 network connection (Data +)
Power
Power supply hot
+Vterm
GND
-
+
POWER
GND
NET B
NET A
Tx/Rx
Unit
Controller
TAP-Stat
Appendix C: Space Thermostat Quick Start
Occupancy Override Time Adjustment
If the occupancy override time needs to be adjusted:
• If the occupancy override is enabled from the space thermostat or the unit
microprocessor, it will override for the period of time set on this menu screen.
• To adjust the temperature override time, enter the following menu options at the
controller, Ctrl Variables/Occupancy. Scroll down at the Occupancy Menu and select
Occ Timed Override. This menu will allow the user to enable occupancy override
from the controller and set override duration.
