The module off-loads the CPU by:

• Direct connection of one incremental encoder per channel
• Direct connection for gate signals (light barrier, etc.) using integrated digital inputs
• A comparison function and output of response via integrated digital output modules

The following functions are provided:

• Two channels for upcounting and downcounting; each 32-bit
• Counting frequency up to 500 kHz (RS 422 encoders)
• Counting range 0 to 32 bit or ±31 bit, as desired
• One-time or periodic counting process
• Single, double or quadruple evaluation
• Can be connected to incremental encoders; e.g., initiators, 24 V encoders or RS 422 encoders (5 V)
• Gate control via levels
• Setting via the digital input
• Counter can be loaded with a predefined starting value
• Comparison function using two user-definable reference values
• Interrupt response when a reference value is reached, zero crossing, range overrun (selectable)
• Output signal (24-V level), controlled by the comparison functions: with jointly specifiable pulse duration or as a continuous signal from the comparison value to the limit of the counting range.

Mode of operation

The FM 450-1 counter module detects pulses from incremental encoders at up to 500 kHz, as a function of directly connectable gate signals. It analyzes the direction of the pulses and compares independently on each channel the respective actual values with two specifiable comparison values.

There are two possibilities available to output the reaction to the process:

• Digital outputs:
  These can be configured via a common register with a selectable minimum pulse or with level switching.
• Backplane bus:
  the FM 450-1 can send an interrupt to the CPU via the integrated backplane bus.

Parameterization

Parameters are assigned with STEP 7 taking into account the parameterization screen forms. A configuring package is available for this purpose.