Siemens SIMATIC S7-300 FM 350-1 - Page 152

Operating Modes, parameters and commands
7.4 Measuring modes
FM 350-1 Counter module
152 Manual, 05/2011, A5E03648639-01
Gate control in isochronous mode
SW gate control: You control operations using the SW gate by setting and resetting the
SW_GATE control bit in the user program. The measurement starts when the control bit is
set, and stops at the time T
i
in the next PROFIBUS DP cycle when the control bit is reset:
 

 
676B*$7(
6:B*$7(
7
'3
7R 7R 7R 7R 7R7
L
7
'3
7
'3
7
'3
7
'3
7
L
7
L
7
L
7
L
0HDVXUHGYDOXH 
3URYLVLRQRIDFWXDOPHDVXUHGYDOXH
3URYLVLRQRIWKHPHDVXUHGYDOXHWKDWZDVYDOLGDWWKHHQGRIWKHPHDVXUHPHQW
0HDVXUHPHQW
'3F\FOH '3F\FOH '3F\FOH '3F\FOH '3F\FOH
Figure 7-38 Starting and stopping a measurement using the SW gate (SW_GATE)
HW gate control: You control a measurement using the HW gate by opening the HW gate to
start the operation, and immediately stop the measurement at the time T
i
by closing the HW
gate:
676B*$7(
7
'3
7R 7R7R7R7R 7
L
   
7
'3
7
'3
7
'3
7
'3
7
L
7
L
7
L
7
L
+:JDWH
0HDVXUHPHQW
0HDVXUHGYDOXH 
3URYLVLRQRIDFWXDOPHDVXUHGYDOXH
3URYLVLRQRIWKHPHDVXUHGYDOXHWKDWZDVYDOLGDWWKHHQGRIWKHSUHYLRXVPHDVXUHPHQW
'3F\FOH '3F\FOH
'3F\FOH
'3F\FOH '3F\FOH
Figure 7-39 Starting and stopping measurements using the HW gate (HW_GATE)