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Showing results for tags 'alarmserver'.
Hello. I am building a program to drive an animated water fountain. I am having a problem with the builtin alarmserver that is available on my Vision 570. The way i have structured my program is this: I am using subroutines and datablocks to get a function block like functionality. However, this means my cycle scan time has reached 70ms. Next i am trying to configure the builtin alarm server. Just for testing, i added two alarms to group 0. Both trigger on value "1". Just as an experiment, on the positive edge of the "one or more alarms is pending" bit that is output by the alarm group function, i am displaying all alarm groups with the show groups FB. The problem that i am noticing is somehow linked to the scan time. Anyway, what happens is that when i trigger one of the alarm bits, the various outputs of the alarm group function (for example number of pending alarms) do not update. They remain at the previous values (0 since at plc start i have no errors). However, if i disable some nets from the main program and bring my cycle scan time down to under 20 msec, the outputs of the alarm group function work when i start triggering alarms. To me, this suggests that the alarm server does not run if the scan time exceeds a certain value, since the code for displaying the alarms is the same in both situations and only works in one. I have tried to find more documentation on this issue but was not able to. Another question would be, how do i change the watchdog timer value ? Is it even possible to change it ?