Process data

Main PDO

Selection of basic process data:

Fig.156: “Process data” tab
A: Selection of data direction: input or output
B: Selection of (optional) PDOs (process data objects)
C: Explanatory notes for PDOs

• Byte/word alignment: By default the EL5101 is operated in normal operation mode with byte alignment and therefore efficiently few process data. In cases where an EtherCAT master requires the process data in word alignment (filled to 16 bit), PDO 0x1A01 and 0x1601 should be used.

Optional PDOs

Optional PDOs, in addition to the main PDO:

• PDO 1 (0x1A02):
• The frequency is determined over 10 ms (fixed) as a number of increments.
• The period (time interval between two positive edges of input A) is determined as often as possible in the unit 500 ns/digit. If no increment event occurs for approx.1.6 seconds, the frequency/period is set to 0.
• Window: A user-defined time window can be parameterized via CoE object 0x8001:02 with the unit 16 µs/digit. During this window time the encoder increments are counted and output in the process record window.

Process data description

Fig.157: Process data description

The process data are generated from CoE objects 0x6000 (inputs) and 0x7000 (outputs).

• Status: Status bits (see section Control and status word)
• Value: Encoder position
• Latch: Latch position
• Frequency: Current calculated frequency
• Period: Period of the last possible measurement
  The refresh rate depends on the cycle time and the current frequency
• Window: Number of edges counted during the time window
• Ctrl: Control bits (see section Control and status word)
• Value: Relevant counter value

• Sync Manager (SM)
• PDO assignment
• Predefined PDO Assignment