Greenheck DOAS v8.1 Reference Manual page 32

Control Variables
Advanced
Backup/Restore
32 Microprocessor Controller for DOAS
Menu
bms w
aTchdog
The BMS watchdog function verifies BMS connectivity. The watchdog is required
for the BMS to take the place of a hardwired sensor. The BMS toggles the
watchdog variable from true to false within the timeout delay. If the timer expires,
the controller falls back to hardwired sensors until the BMS connection can be
established. At this time, a BMS watchdog alarm activates.
The following variables may be used by the BMS in place of hardwired sensors:
• Outside_RH_from_BMS
• Outside_Temp_from_BMS
• Return_RH_from_BMS
• Return_Temp_from_BMS
• Space_1_CO2_from_BMS
• Return_CO2_from_BMS
• Space_RH_from_BMS
• Space_Static_from_BMS
• Space_Temp_from_BMS
s s
ensor ource
The sensor source can be changed to source by BMS through the controller or
by a dedicated BMS point. Reference Points List and in the Appendix for more
detailed point information. The screen to the left is an example of the sensor
source type. Source can be set for local or BMS at this screen.
The Backup/Restore Menus allows the user to create a backup file of setpoints
and configuration variables on a USB drive or in the controller's internal memory.
Connecting to USB Drives
The controller has built-in USB ports for connecting to USB drives. or to the USB
port of a computer. This allows the user to perform various operations including
upgrading an application or OS, saving or retrieving logs, user backups, and
viewing the web user interface.
Connecting a USB cable to a computer shows a screen on the controller that
allows the user to choose whether to access files (disk drive) or the WebUI by
using the arrow buttons.
The controller will either have a USB Type A, USB Type B or Micro USB
dependent on model.
USB Type A
USB Type B