Makel MSA-CM Series User Manual page 20

4 Detailed Functions Description
(defined with "Pre-warning message type") message via "Pre-Warning" CO or both. The Figure 3
suggests a possible time diagram for timer operation when "Timer (default value)" is set to T_d, "Timer
operation mode" is set to "On", "Timer expiration Pre-Warning usage" is set to "Send message +
Invert output", "Timer expiration pre-warning" is set to T_warn and "Pre-warning message type" is
"On"; here the timer is started due to a received "Start" message and runs until expiration.
Figure 3: Timer operation example when Pre-Warning uses output status inversion and message.
Setting "Timer Delay change via Com. Obj." defined if the timer delay can be changed at run-time via
CO, and which is the DPT of the CO with the time delay. The operation has immediate effect, meaning
that if the timer is running and a new time delay, smaller than the already elapsed time, is sent via
"Timer delay (seconds)" CO it will cause the timer to terminate; if the a larger value is sent then
the timer will expire just when the new value is reached. Also to be considered that the pre-warning will
occur (if active) even in the case the new value is closer to expiration than the defined value for pre-
warning; in Figure 4 it's shown a possible scenario that tries to illustrate the previous situation (the device
would be making use of "Timer Delay change via Com. Obj." and "Timer expiration Pre-Warning
usage" set to "Send Message via Pre-Warning CO").
User's Manual Page 20