Switching with preset frequency values

The following settings are required to switch outputs on the basis of specified frequency values. The following applies: n = 0 for output 1, n = 1 for output 2.

Select process data or suitable Predefined PDO Assignment

"1 Ch. Standard, Output"
"1 Ch. Standard, extended DC mode, 64 Bit time stamp, Output"
"1 Ch. Standard, Period mode, Output"
"1 Ch. Standard, Frequency mode, Output"

Select reference value of the switching value

Index 0x8001:2n "Threshold base value" = 2: "Frequency value (2)",

Parameterization frequency or velocity measurement

Parameterization of the frequency or velocity measurement see chapter Frequency measurement and Velocity, speed calculation

Activate automatic switching function

PDO 0x70n1:02 "Control Enable thresholds output" = TRUE

As soon as the automatic switching function is enabled, the switching state specified via the PLC variable is ignored.
Notice If the switching function is enabled at standstill, the output is set according to the last known state. If there is no state message, the output state = FALSE

Specify number of currently valid threshold values

Up to two valid threshold values can be specified that are to be processed (Threshold 1 and Threshold 2)

PDO 0x70n2:11 "Number of output events":

Specify threshold values

Max. two 32-bit threshold values can be specified.
Notice 0 is a valid value, i.e. the output is switched at zero crossing if the threshold value is valid according to the specification in "Number of output events".

  • For "Number of output events" = 1 (hysteresis) select for
    • positive switching logic: "Threshold 1" > "Threshold 2".
    • negative switching logic: "Threshold 2" > "Threshold 1".
  • For "Number of output events" = 2 select for
    • Positive switching logic: "Threshold 1" < "Threshold 2"
    • negative switching logic: "Threshold 1" > "Threshold 2

Status of the output

The status of the output is fixed for each threshold.

  • "Threshold 1":
    PDO 0x70n3:01 "Output state 1" = TRUE
  • "Threshold 2":
    PDO 0x70n3:02 "Output state 2" = FALSE

Duration

Notice When switching with specified frequency or velocity values, no duration can be specified.

Status of the output

The current output status is reported back via the PDOs 0x60n3:01 "Status of digital output" and 0x60n3:02 "Status of tristate".
Note that the process data is updated with the EtherCAT cycle time, but the switching of the output by means of the switching function is asynchronous.

Switch output with a threshold with hysteresis function

Proceed as follows if only a threshold is to be specified for switching the output so that it is switched on when a defined frequency or velocity is reached and switched off again via a hysteresis function when the frequency or velocity falls below a defined value.

Example of the hysteresis function for positive switching logic (n = 0 for output 1, n = 1 for output 2)

1. "Number of output events" = 1
2. Specification of the switching threshold at which the output is to be switched on: "Threshold 1",
the status of the output is fixed at "Output state 1" = TRUE,
an input via the corresponding process data is ignored.
3. Specification of the switching threshold at which the output is to be switched off again "Threshold 2".
For positive switching logic, "Threshold 1" > "Threshold 2" must be selected,
the transition range is to be interpreted as hysteresis.
The current status of the output is reported via the PDOs 0x60n3:01 "Status of digital output" and 0x60n3:02 "Status of tristate".
Please note that the process data is updated with the EtherCAT cycle time, but the switching of the output is asynchronous.

Examples of switching behavior for frequency value specification with hysteresis function:

1. For positive switching logic, select "Threshold 1" > "Threshold 2".
Switching with preset frequency values 1:
Switching behavior for frequency value specification with hysteresis, positive switching logic
2. For negative switching logic, select "Threshold 2" > "Threshold 1".
Switching with preset frequency values 2:
Switching behavior for frequency value specification with hysteresis, negative switching logic

Output switching via two threshold values (n = 0 for output 1, n = 1 for output 2)

If the output is to be switched based on two threshold values, both positive and negative switching logic can be implemented. The threshold values are to be selected as follows:

Example for switching the output with two threshold values with positive switching logic

1. "Number of output events" = 2
2. Specification of the switching threshold at which the output is to be switched on:
"Threshold 1", the status of the output is fixed to "output state" = TRUE,
an input via the corresponding process data is ignored.
3. Specification of the switching threshold at which the output is to be switched off again
"Threshold 2"
4. Select "Threshold 1 < Threshold 2" for positive switching logic
The current status of the output is reported via the PDOs 0x60n3:01 "Status of digital output" and 0x60n3:02 "Status of tristate".
Please note that the process data is updated with the EtherCAT cycle time, but the switching of the output is asynchronous.

Examples Switching behavior with two threshold values:

1. Select "Threshold 1 < Threshold 2" for positive switching logic.
Switching with preset frequency values 3:
Switch output with two threshold values, positive switching logic
2. Select "Threshold 1 > Threshold 2" for negative switching logic.
Switching with preset frequency values 4:
Switch output with two threshold values, negative switching logic