Lenze Global Drive PLC Developer Studio Manual de usuario descargar pdf (Pagina 77)

Drive PLC

System blocks − Extension Board 3

7.3 DFIN_IO_DigitalFrequency (node number 21)

7−9

DrivePLC DE 6.0

Functional sequence

1. The TP is signal−controlled via the digital input X3/I1 of the basic unit or a zero pulse (only if an

encoder is connected).

2. If a TP has occurred, DFIN_bTPReceived_b is set = TRUE.

3. After the start of the task, DFIN_dnIncLastScan_p indicates the number of increments [inc]

counted since the TP.

4. Following, DFIN_bTPReceived_b = FALSE is set.

Note!

It is necessary that all three outputs (DFIN_nIn_v, DFIN_bTPReceived_b and

DFIN_dnIncLastScan_p) are processed in the task even if just one signal is required.

DFIN_nIn_v

 The value DFIN_nIn_v is scaled in increments per millisecond.

(INT) 16384 corresponds to 15000 rpm. See chapter 1.2.7, "Signal types and normalisations".

(^ 1−8)

 For every task in which DFIN_nIn_v is used, the operating system creates an individual counter

that is reset after every start of the task (task−internal process image).

 For reliable TP generation, DFIN_nIn_v must not be used in the PLC_PRG.

Example (DFIN_nIn_v in a 10 ms task):

 When the 10 ms task starts, the value of the integrator is stored in a local area of the task and

the integrator is reset. The value in the local area gives an average value in increments per 1

ms.

 If a position value is to be derived from this value, then it must be multiplied by

SYSTEM_nTaskInterval / 4 to get the result in increments per 10 ms, as in the example.

Example: In a 1 ms task SYSTEM_nTaskInterval is 4 (4 x 250 s = 1 ms)

 For Lenze FBs, this process has already been implemented in the FBs.

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Lenze Global Drive PLC Developer Studio Manual de usuario Pagina 77