Technical data

Table Of Contents
System Software for S7-300/400 System and Standard Functions - Volume 1/2
A5E00709327-01
6-1
6 SFCs for Handling Run-Time Meters
6.1 Runtime Meters
Introduction
The CPUs have a number of runtime meters (refer to the data sheets of your
CPUs).
If your CPU is equipped with 16-bit runtime meters, you can set, start, stop or
read them with the SFCs 2, 3 and 4.
If your CPU is equipped with 32-bit runtime meters, you can set, start, stop or
read them with SFC 101 "RTM".
Note
SFCs 2, 3 and 4 can also be used for 32-bit runtime meters. In this case however,
the runtime meters operate in a 16-bit mode (Range of values: 0 to 32767 hours).
See also: Data Record of the Partial List Extract with SSL-ID W#16#0132 Index
W#16#000B.
Application
You can use a runtime meter for a variety of applications:
For measuring the runtime of the CPU
For measuring the runtime of controlled equipment or connected devices.
Characteristics of the Runtime Meter
When it is started, the runtime meter begins to count starting at the last recorded
value. If you want it to start at a different initial value, you must explicitly specify this
value (SFC 2 or SFC 101 with MODE=4). If the CPU changes to the STOP mode,
or you stop the runtime meter, the CPU records the current value of the runtime
meter. When a warm restart or a cold restart of the CPU is executed, the runtime
meter must be restarted (SFC 3 or SFC 101 with MODE=1).
Range of Values
CPU with 16-bit runtime meters: 0 to 32 767 hours
CPU with 32-bit runtime meters: 0 to (2E31) -1 hours = 2.147.483.647 hours