Since the HS3 RCS serial plugin is essentially non-functional and no longer supported (especially in multiple thermostat and zone controller environments) I am forced to control the older RCS stats and ZCV4 zone controllers by running HS2 and controlling the stats through the Jon00 connector.
There is a long documented bug in the HS2 RCS plugin that affects setpoints on RCS stats that have dual setpoints for heating and cooling:
http://board.homeseer.com/showthread.php?t=134464
The HS2 RCS plugin erroneously alters the cooling setpoint anytime the heat setpoint is set from the plugin or an event. This can cause the cooling system to cycle on for the minimum run time (MRT) unintentionally. For years I have put up with this since the bug was never corrected, probably to maintain backwards compatibility with the earlier single setpont RCS stats.
This behavior can be avoided by setting the system mode to "off" prior to changing the heat and cool setpoints then resetting the system mode to "auto" or "cool" or "heat" after changing any setpoint (either through an event or script). It is still critical to change the heat setpoint first then the cool setpoint since it is the heat setpoint that contains the bug that also sets the cool setpoint and setting the cool setpoint after the heat setpoint corrects the cool setpoint error (see discussion in above thread regarding SPH/SPC and SP).
By taking the system offline (setting the system mode to "off") during the time the setpoint change data is being written to the stats you can avoid the unintentional compressor cycling every time a heat setpoint is changed. Just remember to have the event or script re-enable the system mode after the changes are made.
There is a long documented bug in the HS2 RCS plugin that affects setpoints on RCS stats that have dual setpoints for heating and cooling:
http://board.homeseer.com/showthread.php?t=134464
The HS2 RCS plugin erroneously alters the cooling setpoint anytime the heat setpoint is set from the plugin or an event. This can cause the cooling system to cycle on for the minimum run time (MRT) unintentionally. For years I have put up with this since the bug was never corrected, probably to maintain backwards compatibility with the earlier single setpont RCS stats.
This behavior can be avoided by setting the system mode to "off" prior to changing the heat and cool setpoints then resetting the system mode to "auto" or "cool" or "heat" after changing any setpoint (either through an event or script). It is still critical to change the heat setpoint first then the cool setpoint since it is the heat setpoint that contains the bug that also sets the cool setpoint and setting the cool setpoint after the heat setpoint corrects the cool setpoint error (see discussion in above thread regarding SPH/SPC and SP).
By taking the system offline (setting the system mode to "off") during the time the setpoint change data is being written to the stats you can avoid the unintentional compressor cycling every time a heat setpoint is changed. Just remember to have the event or script re-enable the system mode after the changes are made.