Notes For Direct Data Entry With Programmers Or Operator Panels - Siemens SIMATIC S5 Manual

Notes on Operation
You then continue to the limit switch with "Start forwards" and at the start/stop
rate. The traversing movement stops immediately when the limit switch is
reached. You can re-establish this reference point at any time with step accuracy
if you approach it with the same pulse frequency from the same direction.
Note:
Contact bounce at the REF, EMINUS and EPLUS inputs are compensated for by
the module. This delays signal processing. To enable the IP 267 to reproduce
reference points exactly, the periode of the step frequency must be greater
than the signal delay. You must therefore approach the reference points with
step frequencies of less than 100 Hz. In the case of start/stop rates greater
than 100 Hz, you can decrease the relevant step frequency by the reduction
factor R in the current positioning job - i.e. without reconfiguring.
5.5 Notes for Direct Data Entry with Programmers or Operator
Panels
You can transfer data from programmers or operator panels (OPs) to the PC.
When the transfer command is entered in the "FORCE VAR" mode of the
programmer or from the operator panel, the interface transfers data byte-wise to
the CPU at a baud rate of 9600 bits/s (=1 byte per 850 µs).
When the first byte has been completely transferred to the CPU, the processor in
the CPU initiates an interrupt. Cyclic processing of the program is interrupted and
the transferred byte is written into the PIQ. Cyclical processing of the program is
then continued until the second byte has been completely transferred by the
interface. As soon as the second byte has been completely transferred to the CPU,
the processor in the CPU initiates a further interrupt in order to transfer the
second byte to the PIQ, and so on.
5-10
IP 267
EWA 4NEB 812 6061-02a