Siemens SIMATIC S5 IP 281 Equipment Manual page 94

Commissioning the Counter Module
Gate status Indicates the current status of the internal gate (-t section 6.6)
Counter running The CRS (counter, bit O) of the applicable counter is entered in the status
register.
This bit indicates the current direction of counting. When stopped, the di-
Counting direction
rection of counting last indicated is retained.
This bit indicates whether the digital output is active (24 V level on DQ).
Zero crossing This bit is set when the counter reaches the value O during counting.
Reading the register causes the bit to be reset.
Set This bit is set each time the counter is loaded. Reading the register
causes the bit to be reset.
This bit is set when the counter exceeds the upper counting range limit
Overflow
This bit is set when the counter passes below the lower counting range limit
Underflow
5 – 6
@.SiemensA(31992, C)rder No:6E85998-0KP21
R 11/92