Rockwell Automation 1752-L24BBBE SmartGuard 600 Controllers User Manual - Manual (Page 172)

172 Rockwell Automation Publication 1752-UM001E-EN-P - June 2014
Chapter 12 Monitor Status and Handle Faults
Monitoring I/O Maintenance
Information You can configure a maintenance mode and alarm threshold for each local input,
test output, and local output terminal by using the Maintenance tab of the
Controller Properties dialog box in RSNetWorx for DeviceNet software. You can
configure a terminal for either contact operation counter or total on-time
monitoring.
Contact Operation Counter Monitoring
This maintenance function counts the number of off-to-on operations at a local
input, test output, or local output terminal and stores the count internally in
nonvolatile memory.
Total On-time Monitoring
This maintenance function times how long a local input, test output, or
local output is on and stores that total on-time internally in nonvolatile
memory. The monitor function checks whether the connected device is on
at intervals of one second. If the device is on for less than one second, the
total on-time may not be precise.
EXAMPLE Calculating Total On-time with 0.5 Second On Pulses
ATTENTION: In this first example, the bit is actually on for 0.5 s x 3 = 1.5
s. However, the bit is on only once when the status is checked, so the total
on-time is measured as 1 s.
ATTENTION: In this second example, the bit is actually on for 0.5 s x 3 =
1.5 s, but the bit is on twice when the status is checked, so the total on-
time is measured as 2 s.
0.5 s
Measured 1 Time/Second
ON
OFF
0.5 s
Measured 1 Time/Second
ON
OFF