Siemens Simatic S7 Series System Manual page 244

Program instructions
7.6 Counters
Disabling a high-speed counter (any mode)
The following steps describe how to disable the HSC0 high-speed counter (any mode):
1. Load SMB37 to disable the counter:
SMB37 = 16#00
– Disables the counter
2. Execute the HSC instruction to disable the counter.
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System Manual, 09/2015, A5E03822230-AC
S7-200 SMART