Job Valid rangeWriting 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 acounter, 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 measurementThe 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 ofthe SFB are stored.n Among others the SFB 48 contains a request interface. Hereby you get read andwrite access to the registers of the frequency meter.n So that a new job may be executed, the previous job must have be finished withJOB_DONE = TRUE.n Per channel you may call the SFB in each case with the same instance DB, since thedata 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 CommentLADDR INPUT WORD 0.0 300h This parameter is not evaluated.Always the internal I/O peripheryis addressed.CHANNEL INPUT INT 2.0 0 Channel numberSW_GATE INPUT BOOL 4.0 FALSE Enables the Software gateJOB_REQ INPUT BOOL 4.3 FALSE Initiates the job (edge 0-1)JOB_ID INPUT WORD 6.0 0 Job IDJOB_VAL INPUT DINT 8.0 0 Value for write jobsSTS_GATE OUTPUT BOOL 12.0 FALSE Status of the internal gateMEAS_VAL OUTPUT DINT 14.0 0 Evaluated frequencyJOB_DONE OUTPUT BOOL 22.0 TRUE New job can be started.Latch functionDescriptionParametersVIPA SPEED7 Integrated StandardSystem Function Blocks > SFB 48 - FREQUENC - Frequency measurementHB00 | OPL_SP7 | Operation list | en | 18-30 765
