YASKAWA VIPA SPEED7 - SFB 1 - CTD - Down-Counter

Status of the counter:
n Q is set to "1" if CV ≥ PV (current count ≥ preset value)
n else Q = "0"
Current count:
n possible values: 0 ... 32767
14.2.2 SFB 1 - CTD - Down-counter
The SFB 1 can be used as Down-counter. Here you have the following characteristics:
n If the signal state at the down counter input CD changes from "0" to "1" (positive
edge), the current counter value is decremented by 1 and displayed at output CV.
n When called for the first time with LOAD = "0" the counter value corresponds to the
preset value at input PV.
n When the lower limit of -32767 is reached the counter will not be decremented any
further, i.e. all rising edges at input CU are ignored.
n When a "1" is applied to the LOAD input then the counter is set to preset value PV
irrespective of the value applied to input CD.
n Output Q has signal state "1" if CV ≤ 0.
n When it is necessary that the instances of this SFB are initialized after a restart, then
the respective instances must be initialized in OB 100 with LOAD = 1 and PV =
required preset value for CV.
Parameter Declaration Data type Memory block Description
CD INPUT BOOL I, Q, M, D, L, con-
stant
Count input
LOAD INPUT BOOL I, Q, M, D, L, con-
stant
Load input. LOAD takes precedence
over CD.
PV INPUT INT I, Q, M, D, L, con-
stant
Preset value
Q OUTPUT BOOL I, Q, M, D, L Status of the counter
CV OUTPUT INT I, Q, M, D, L Current count
Count input:
This counter is decremented by 1 when a rising edge (with respect to the most recent
SFB call) is applied to input CU.
Load input:
When a 1 is applied to the LOAD input then the counter is set to preset value PV irre-
spective of the value applied to input CD.
Preset value:
The counter is set to preset value PV when the input LOAD is “1”.
Q
CV
Description
Parameters
CD
LOAD
PV
VIPA SPEED7
Integrated Standard
System Function Blocks > SFB 1 - CTD - Down-counter
HB00 | OPL_SP7 | Operation list | en | 18-30 730