Specifications
Special Memory (SM) Bits
C-9
S7-200 Programmable Controller System Manual
C79000-G7076-C233-01
SMB36 to SMB65: HSC0, HSC1, and HSC2 Register
As described in Table C-14, SMB36 through SM65 are used to monitor and control
the operation of high-speed counters HSC0, HSC1, and HSC2.
Table C-14 Special Memory Bytes SMB36 to SMB65
SM Byte
Description
SM36.0 to
SM36.4
Reserved
SM36.5 HSC0 current counting direction status bit: 1 = counting up
SM36.6 HSC0 current value equals preset value status bit: 1 = equal
SM36.7 HSC0 current value is greater than preset value status bit: 1 = greater than
SM37.0 Active level control bit for Reset:
0= Reset is active high, 1 = Reset is active low
SM37.1 Reserved
SM37.2 Counting rate selection for quadrature counters:
0 = 4x counting rate; 1 = 1 x counting rate
SM37.3 HSC0 direction control bit: 1 = count up
SM37.4 HSC0 update the direction: 1 = update direction
SM37.5 HSC0 update the preset value: 1 = write new preset value to HSC0 preset
SM37.6 HSC0 update the current value: 1 = write new current value to HSC0 current
SM37.7 HSC0 enable bit: 1 = enable
SMB38
SMB39
SMB40
SMB41
HSC0 new current value
SMB38 is most significant byte, and SMB41 is least significant byte.
SMB42
SMB43
SMB44
SMB45
HSC0 new preset value
SMB42 is most significant byte, and SMB45 is least significant byte.
SM46.0 to
SM46.4
Reserved
SM46.5 HSC1 current counting direction status bit: 1 = counting up
SM46.6 HSC1 current value equals preset value status bit: 1 = equal
SM46.7 HSC1 current value is greater than preset value status bit: 1 = greater than
SM47.0 HSC1 active level control bit for reset: 0 = active high, 1 = active low
SM47.1 HSC1 active level control bit for start: 0 = active high, 1 = active low
SM47.2 HSC1 quadrature counter rate selection: 0 = 4x rate, 1 = 1x rate
SM47.3 HSC1 direction control bit: 1 = count up
SM47.4 HSC1 update the direction: 1 = update direction
SM47.5 HSC1 update the preset value: 1 = write new preset value to HSC1 preset
SM47.6 HSC1 update the current value: 1 = write new current value to HSC1 current