Job Valid range
Writing pulse duration* 0 ... 510ms
*) Only even values allowed. Odd values are automatically rounded.
As soon as during a count process an edge 0-1 is recognized at the "Latch" input of a
counter, the recent counter value is stored in the according latch register.
You may access the latch register via LATCHVAL of the SFB 47.
A just in LATCHVAL loaded value remains after a STOP-RUN transition.
14.2.18 SFB 48 - FREQUENC - Frequency measurement
The SFB 48 is a specially developed block for compact CPUs for frequence measure-
ment.
n The SFB FREQUENC should cyclically be called (e.g. OB 1) for controlling the fre-
quency measurement.
n The SFB is to be called with the corresponding instance DB. Here the parameters of
the SFB are stored.
n Among others the SFB 48 contains a request interface. Hereby you get read and
write access to the registers of the frequency meter.
n So that a new job may be executed, the previous job must have be finished with
JOB_DONE = TRUE.
n Per channel you may call the SFB in each case with the same instance DB, since the
data necessary for the internal operational are stored here. Writing accesses to out-
puts of the instance DB is not permissible.
n With the SFB FREQUENC (SFB 48) you have following functional options:
– Start/Stop the frequency meter via software gate SW_GATE
– Read the status bit
– Read the evaluated frequency
– Request to read/write internal registers of the frequency meter.
Name Declaration Data type Address
(Inst.-DB)
Default value Comment
LADDR INPUT WORD 0.0 300h This parameter is not evaluated.
Always the internal I/O periphery
is addressed.
CHANNEL INPUT INT 2.0 0 Channel number
SW_GATE INPUT BOOL 4.0 FALSE Enables the Software gate
JOB_REQ INPUT BOOL 4.3 FALSE Initiates the job (edge 0-1)
JOB_ID INPUT WORD 6.0 0 Job ID
JOB_VAL INPUT DINT 8.0 0 Value for write jobs
STS_GATE OUTPUT BOOL 12.0 FALSE Status of the internal gate
MEAS_VAL OUTPUT DINT 14.0 0 Evaluated frequency
JOB_DONE OUTPUT BOOL 22.0 TRUE New job can be started.
Latch function
Description
Parameters
VIPA SPEED7
Integrated Standard
System Function Blocks > SFB 48 - FREQUENC - Frequency measurement
HB00 | OPL_SP7 | Operation list | en | 18-30 765
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