Specifications

CPU Memory: Data Types and Addressing Modes
5-11
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
Addressing the High-Speed Counters (HC)
High-speed counters are designed to count very high-speed events independent of
the CPU scan. High-speed counters have a signed, 32-bit integer counting value
(or current value). To access the count value for the high-speed counter, you
specify the address of the high-speed counter, using the memory type (HC) and
the counter number (such as HC0). The current value of the high-speed counter is
a read-only value and, as shown in Figure 5-8, can be addressed only as a double
word (32 bits).
Format: HC [high-speed counter number] HC1
HC 2
HC2
31
MSB
0
LSB
High-speed counter number
Area identifier (high-speed counter)
Least significantMost significant
Byte 0Byte 1Byte 2Byte 3
Figure 5-8 Accessing the High-Speed Counter Current Values