Orion-M
3.4 FDC Orion-M
CONFIGURING THE UDC2500/3200 CONTROLLER
3.4 Loop Permissions
The Orion-M iSeries configuration provides permissions which can be set to allow the control loop set point,
auto/manual and auto tune operations to be performed at the loop control itself as well as through the Orion-
M. These can allow an operator to make changes at the loop control in cases where the Orion-M interface is
located in a remote location.
3.4.1
Set Point Permission Exception
If the control loop is configured to operate under cascade control or is configured as an RH wet bulb loop
type, the set point for the loop is generated by logic within the Orion-M. The loop will not function as
configured unless the se point is constantly set by the Orion-M. Thus, any change made at the loop control
will be overridden by the Orion-M. If local adjustment at the loop control may be required for any reason, loop
set point communications must be interrupted via a digital input to the Orion-M configured as ‘loop SP comms
disable’.
In addition, the Honeywell controls will enter the computer set point mode (CSP) once they receive any set
point command from the Orion-M. This will lock out adjustments from the keypad at the controller. The
Orion-M is designed to send the ‘shed timer reset’ command to the UDC controller to take it out of computer
set point control when the set point permission is enabled. This allows control via the keypad of the
controller. However, during profile operation and after the profile completes, the UDC will remain under
computer set point control. In order to deactivate CSP, a single set point must be sent from the Orion-M in
order to unlock it. Triggering a digital input configured as ‘loop SP comms disable’ will also take the UDC
controls out of computer set point control.
3.4.2
Auto/Manual Permission Requirement
The Honeywell controller provides the ability to initiate manual mode or ‘failure transfer mode’ through a
digital input on the controller. If this function is used, the loop permission for auto/manual operation must be
enabled. If this permission is not enabled, a communication error will occur at the Orion-M. This is due to the
fact that without the permission enabled, the Orion-M will try and force the controller back to auto mode if it
goes into manual operation via the digital input.
Since the digital input on the UDC controller is an override condition, it will deny the auto mode command
from the Orion-M. The Orion-M then has to respond with a communication error, since the controller did not
follow the command given. By enabling the auto/manual permission, the Orion-M will accept the manual
mode force at the UDC controller.
Summary of Contents for Orion-M
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