SERCOS Measurement

Drive parameters

For use of the measurement function, the following parameters must be set in the drive:

Real time control and status bits used
Measuring probe to be used
Measuring probe control parameters
Measured value in the cyclic telegram

Refer to the drive documentation for details of the parameters supported by the relevant drive.

Additional it is possible that a digital input of the drive has to be configured as probe latch. Please refer here also to the documentation of the relevant drive.

Real time bits

For measurement both real time status bits and one real time control bits are necessary.

With the real time status bits the following information is transferred to the NC kernel:

Edge at measurement input detected (measurement done)
Measurement equipment actuated.

Also, a real time control bit is necessary to enable the edge detection of the probing input in the drive.

The assignment of the real time status and control bits used by the NC-kernel is done with P-AXIS-00060. Also drive parameters must be set accordingly.

The following table shows the assignment of the real time bits used by the NC-kernel dependent on the value of P-AXIS-00060.

P-AXIS-00060	Control bits	Status bits
	Measurement Enable	Measurement done	Measurement equipment Actuated
0, no entry	Realtime control bit 1	P-AXIS-00106	Realtime status bit 2
1	Realtime control bit 1	Realtime status bit 1	Realtime status bit 2
2	Realtime control bit 2	Realtime statusbit 2	Realtime statusbit 1

	It is recommended to set P-AXIS-00060 to either 1 or 2. The value 0 is just for backward compatibility with older versions of the NC-kernel and requires additional settings (P-AXIS-00106).

Measuring probe control parameters

The measuring probe control parameter (S-0-0169) is used to configure which measuring probe and which edge of the measured signal is to be used in the drive. Depending on this parameter, the registered positions are stored in different SERCOS identifications, and these SERCOS identifications must then be transferred in the drive's cyclic actual value telegram.

Measuring probe/edge	Measuring probe control parameter S-0-0169	Measured value identification
Measuring probe 1, positive edge	S-0-0169 = 1	S-0-0130
Measuring probe 1, negative edge	S-0-0169 = 2	S-0-0131
Measuring probe 2, positive edge	S-0-0169 = 4	S-0-0132
Measuring probe 2, negative edge	S-0-0169 = 8	S-0-0133

Parameterization of the cyclic telegram

The measured value identification specified in the table above must be configured in the cyclic actual value telegram depending on the measuring probe control parameter.

Axis parameters

For SERCOS drives, the following entries must be assigned in the axis parameter lists:

P-AXIS-00116

Measurement via SERCOS bus:

kenngr.mess_signal_sercos 1

P-AXIS-00113

Latching if positive measured signal edge:

kenngr.mess_neg_flanke 0

Parameterizing a SERCOS drive

The steps necessary to parameterize a SERCOS drive are presented in a flowchart on the following pages.

Example

The following parameters are necessary in the drive and in the NC kernel for configuration of the measuring function of a SERCOS drive with the rising edge of measuring probe 1 using the real time and status bits 1.

Axis parameters

kenngr.hub_messtaster      2000
kenngr.vb_messen           2000
kenngr.messachse           1
kenngr.mess_signal_sercos  1
kenngr.echtzeit_bit_nr     1

Cyclic telegram

Identification S-0-0130 must also be configured when configuring the cyclic telegram:

Drive

The real time bits 1 and measuring probe 1 are used:

S-0-0301 = 405 (real time control bit 1 = measuring probe 1 enabled)
S-0-0305 = 409 (real time status bit 1 = probe 1, positive latched)
S-0-0307 = 401 (real time status bit 2 = measuring probe 1)

Measuring probe control word

Value 1 must be entered into the measuring probe control word:

S-0-0169 = 1 (measuring probe 1 positive edge)