OM AGSD-1
37
Network Defaults
The network set point default values are used only for the LONworks protocol. Digital
index 10 determines whether the network defaults should be loaded at startup. The startup
process is as follows.
Immediately after the controller powers up, the protocol is checked. If the protocol is
LONworks, then the current status of the BAS unit enable set point, digital 1, is stored in a
temporary location and the BAS enabled set point is set to disable. A ten-second timer
should lapse, then the “ignore network defaults” setting is checked. If this is set low, then
the defaults for BAS cool set point, network limit, unit enable, and unit mode will be
loaded. If the setting is set high, then no defaults are loaded and the status of the BAS
enable set point is restored to the original value.
Unit Full Load/Circuit Available Status for CSM
A unit full load flag and circuit available flags are set for use by the CSM. These flags tell
the BAS system when the unit is running at the maximum available capacity, and which
circuits are available to the BAS for more capacity.
The full load flag is set when either of the following are true:
•
-Each circuit is either running at maximum capacity or is disabled
•
-Unit capacity is greater than or equal to the unit capacity limit
The circuit available flag for each circuit is set when all the following are true:
•
-Circuit is communicating on pLAN
•
-Unit Control Source = BAS
•
-[Remote switch is closed AND Unit switch is closed AND Unit state = Off] OR
Unit state = Auto
•
-Low OAT lock condition does not exist
•
-Circuit is enabled
The unit full load flag is represented by bit 0 of integer index 22. Circuit one available flag
is represented by bit 1, and circuit two available flag is represented by bit 2.
Digital Output Parameters
Type Index I/O
Description
Details
D
2
O Chiller enable status
Set whenever the chiller is enabled by all settings and switches
D
3
O Active alarm indicator Set when any alarm is active. Active events do not set this output
D
4
O Chiller run enabled
Set when the unit state is auto
D
5
O Chiller local control
Set when the unit control source is set to keypad or switches.
D
6
O Chiller capacity limited
Set when a unit capacity limit is active, any circuit is disabled, or
any circuit is limited in capacity.
D
7
O Evaporator water flow
Set when evaporator flow switch is closed
The MicroTech II controller is equipped with the Protocol Selectability
™
feature, an
exclusive McQuay feature that provides easy unit interface with a building automation
system (BAS). If the unit will be tied into a BAS, the controller should have been
purchased with the correct factory-installed communication module. The modules can also
be added in the field during or after installation.
Summary of Contents for AGS 225D
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