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AC500: The function "fast counter" is available in S500 I/O modules as of firmware version V1.3.

AC500-eCo: The function "fast counter" is available in onboard I/Os of PM50x2 processor modules. According to the processor module type, the fast inputs have different functionality or frequency.

Integrated fast counters are only available for digital I/O modules.

The digital I/O modules on the I/O bus contain two fast counters each.

If the counter is used, it needs up to 2 digital inputs and one digital output.

If the fast counter is deactivated, the inputs and outputs reserved for the counter can be used for other tasks.

⮫ “Fast counter”.

A fast counter is available in the following constellations:

  • In digital I/O modules, connected to an AC500 processor module.

  • Processor modules PM50x2 with onboard I/Os

  • In CANopen communication interface modules.

  • In Modbus, PROFIBUS and PROFINET communication interface modules and in the connected digital I/O modules.

  • In digital I/O modules, connected to an EtherCAT communication interface module.

Fast counter integrated in S500 modules

The following table shows the S500 modules which contain a fast counter and which of the digital inputs and outputs are reserved for the counter.

Module

Assigned inputs 1)

Assigned output

Remarks

Channel A

Channel B

Channel C 2) or (CF)

DA501

DC16

DC17

DC18

The counter function is not available if the modules are mounted on the communication interface modules CI581-CN or CI582-CN

DA502

DC16

DC17

DC18 - in mode 1 and mode 2

DO0 - in mode 101 and mode 102 3)

DC522

C8

C9

C10

DC523

C16

C17

C18

DC532

C24

C25

C26

DI524

I24

I25

No hardware output available

DX522

I0

I1

The counter does not activate any relay output

 

CI501‑PNIO, CI541‑DP, CI581‑CN, CI521‑MODTCP

DI0

DI1

DO0

 

CI502‑PNIO, CI542‑DP, CI582‑CN; CI522‑MODTCP

DI8

DI9

DO8

1) The two hardware inputs (channels A and B) are also and always available within the normal process image, irrespective of the operating mode of the counter.

2) The hardware output channel C is activated by the fast counter only in the operating modes 1 and 2.

3) Especially for module DA502: The counter operating mode 101 is the same as mode 1, but the assigned output is DO0 instead of DC18. Also the counter operating mode 102 is the same as mode 2, but the assigned output is DO0 instead of DC18.

The counter function is performed within the communication interface module and, accordingly, in the digital I/O module(s). It works independently of the user program and is therefore able to respond quickly to external signals. A simultaneous counter operation of several digital I/O modules is possible.

Each module counter can be configured for one out of 10 possible modes. The desired operating mode is selected in the PLC configuration using module parameters. After that, it is activated during the initialization phase (power-on, cold start, warm start).

The data exchange to and from the user program is performed using input and output operands. While integrating a module containing a fast counter in the PLC configuration, the necessary operands are created and reserved immediately. Thus, a counter implementation carried out later on does not cause an address shift.

Features independent of the fast counter operating mode

  • The pulses at the fast counters' inputs or the evaluated signals of the traces A and B in case of incremental position sensors are counted.

  • The counting frequencies of the communication interface modules of PROFINET, PROFIBUS and CANopen are max. 200 kHz (in modes 1 to 6), max. 50 kHz (in mode 7), max. 35 kHz (in mode 9), and max. 20 kHz (in mode 10).

  • If the modules DA501, DC522, DC523, DC532 are used, each counting input must be circuited externally in series with a resistor of 470 W / 1 W, in order to safely avoid influences from the deactivated module outputs to the connected sensors.

  • The positive signal edges are counted, if not noted differently.

  • By setting the operating mode 0, the counting function is switched off. In this case, the reserved inputs and outputs can be used for other tasks. Simultaneous use of these terminals for the fast counter and other signals must be avoided.

  • The fast counter's actual value is provided as a double word (32 bits).

  • The fast counter can count upwards in all operating modes. It counts beginning at the start value (set value) up to the end value (max. from 0 to 4,294,967,295 or hexadecimal from 00 00 00 00 to FF FF FF FF. After reaching 4,294,967,295, the counter jumps with the next pulse to 0. When the counter reaches the programmed end value, the counter output is stored permanently as CF = TRUE (end value reached). Only when the fast counter is set again (set value), CF is reset to FALSE.

Further information