Issue
Is it possible to use Control Description (command) delays on MR controllers?
MR (Micro Regulator) DO points not turning ON (or not turning OFF) - sticking.
Environment
I/NET Seven
MR (Micro Regulator) Controllers
Cause
The Control Description command delay was not implemented in the MR as it was not intended to be used for control of multiple high power devices, which this feature was designed for; also, the MR does not have the memory capability to support the timer queue to handle it.
Note: The Control Description command delay does function within the SLI (7793 / 7798B1 / 7798C) although this function is supported here it is not intended for the control of multiple subLAN devices, such as the MR. You should not rely on this control function from the SLI. Undesired results can be expected if this is implemented and is not supported.
Resolution
The Control Description Command Delay is not supported within subLAN devices and should not be implemented. Alternative methods of delaying startup of control devices are:
- Using Time schedules; the Master / Slave time schedules feature. Within the slave schedules you are able to delay / adjust the start time by minutes. The combination of using Master / Slave ATS and Host ATS provides a powerful and simple user interface in modifying all the Master Schedules from a single location. Refer to TCON 300 Chapters 4 and 7.
- MR Functions (DDC); If your control delays are required within the MR, a method available to use is the MR-DDC Relay modules are the delay before break (DDB) or delay before make (DBM) timers. An even simpler method would be to stagger scan rates (using prime numbers) within your MR Function DDC modules. Refer to TCON 300 Chapter 13. The DDC modules have there own scan rates and control the point based on this scan rate and will override any Resident I/O Point scan rate defined on these output points.
- Programmer timers from within the SLI which the control critical items of plant and require a staggered startup procedure.