Registration v1

One machine revolution is defined by Pulses/Rev and floating-point Scaler parameters.

The event and count inputs are freely connectable from any single Encoder or FI function block in any smarty on the local network.

The fraction of a revolution between a master and a slave event is measured.

The setpoint is the desired fraction, from 0.0000 to 0.9999, of a revolution at which the slave event is expected to occur. The function block output is the error from the setpoint.

A window, 0.0000rev to 0.5000rev, is set up around the setpoint. If the error is outside of the window, it is clamped at + or - the window value depending on whether the error exceeds 0.5 times the measured period.

Note - The maximum error output is 0.5 times the measured period.

Out of Window and Missing Event outputs are provided. Missing Event is active if the master or slave events are not present during any cycle or where the measured period exceeds 3.3 revolutions. The error tracks at the last value prior to the missing event.

Application Example - Registration on Shaft Lock

Examples include print cylinder registration and continuous cut-to-length. The material and print or cut head are locked and corrections are applied from the registration loop.

In the following SFD drawing, the primary control is from a well-calibrated and tuned shaft lock system.

Registration error is fed into a Sampled Average function block. The number of samples to be averaged is determined for the system. An Event One Shot function block triggers a new sample for each machine revolution.

The sampled average directly offsets the position demand in the shaft lock loop.

Application Example - Registration on Motion Control, Servo Haul-Off

Examples include bag sealer-cutters with print registration, sheeters, and folders. The servo must haul-off the precise length of material during the allowable period after the cut and prior to the commencement of the next cut.

In the following SFD drawing, the primary control is from a well-tuned motion control loop using Trapezoid Motion function block.

Registration error is fed into a Sampled Average function block. The number of samples to be averaged is determined for the system. An Event One Shot function block triggers a new sample for each machine revolution.

The sampled average directly offsets the position demand in the motion control.

• Available only in the dw2xx-v2 series products
• Requires library: Precision Motion (option -39)
• Firmware versions 0x210C and later

Master Event

The event input is connectable from any single encoder marker, digital input, or FI event function block in any smarty on the local network.

Slave Event

The event input is connectable from any single encoder marker, digital input, or FI event function block in any smarty on the local network.

Count

One machine revolution is defined by Pulses/Rev and floating-point Scaler parameters.

The count input is freely connectable from any single Encoder or FI function block in any smarty on the local network.

Window

The setpoint is the desired fraction, from 0.0000 to 0.9999, of a revolution at which the slave event is expected to occur. The function block output is the error from the setpoint.

A window, 0.0000rev to 0.5000rev, is set up around the setpoint. If the error is outside of the window, it is clamped at + or - the window value.

Setpoint

The desired fraction, from 0.0000 to 0.9999, of a revolution at which the slave event is expected to occur. The function block output is the error from the setpoint.

Status

The function block Status is Fault and the function block output is zero if the count input is not updated for a period longer than approximately twenty times the timebase, i.e. 100ms, by default.

Out of Window

A window, 0.0000rev to 0.5000rev, is set up around the setpoint. If the error is outside of the window, it is clamped at + or - the window value and this flag is asserted.

Missing Event

Active if the master or slave events are not present during any cycle or where the measured period exceeds 3.3 revolutions. The error tracks at the last value prior to the missing event.

Output

The fraction of one machine revolution representing the measured position error from the setpoint.

Master Measured Period

The measured period between the last two master events in terms of one machine revoltion.

Slave Measured Period

The measured period between the last two slave events in terms of one machine revoltion.