2.1   Power Connector J₀

2.1.1 J₀ Pin Assignment

Pin Assignment of J₀ Connector (M12 A-Coding Binder 09-3491-600-12 - male)

Signal Description

Open

Trigger Schematics

2.1.2   Electrical Specification: Camera Power Supply

Voltage/Current Overview

2.1.3   Electrical Specification: Digital PLC I/O, Encoder

Electrical Specifications

2.1.3.1   Connection of PLC, Encoder inputs VC nano 3D-Z Series

2.1.3.2   Connection of PLC outputs VC nano 3D-Z Series

2.1.4   Encoder input specification VC nano 3D-Z Series

It is possible to connect the following encoder signals: ENC A, ENC /A, ENC B, ENC /B, ENC Z. There is no connection provided for signal ENC /Z.

Supported Encoder Connection Configurations

Due to noise and signal bouncing the configuration using only ENC A signal is not recommended.

Pins not used for the encoder can be used as GPIO inputs.

It is possible to swap the signals A and B per software.

The maximum encoder frequency is limited to 200 kHz.

2.1.4.1   Encoder Counter

All internal encoder values represent positions with microstep resolution:
A counter is used internally for counting the full-steps (Bits 31 to 2), whereas the microsteps (Bits 2 to 0) are directly derived from the encoder signals ENC A and ENC B.

The ENC Z signal is detected during microsteps 1 and 2. It resets the full-step counter without resetting the value of the microstep: I.e. the output value during reset can be 0, 1, 2 or 3 depending on the microstep position of the encoder.

If the ENC Z signal is used, the user must program the full-step resolution of the encoder for correct operation, else triggers may not work anymore after some cycles. This number is usually documented at the data sheet of the encoder device. The encoder counts even before the first ENC Z signal is detected. Until then the encoder counter value may be considered as invalid. It is a common practice to calibrate the encoder, moving it to a zero position (reference) first. For your convenience the GPIO input signal 28 is provided indicating that a first ENC Z impulse has been detected. Loss of calibration is indicated if the GPIO input signal 27 is set. This may happen if the ENC Z signal is inconsistent with the full-step resolution. This may occur due to noise, broken cable or a wrong setting for the encoder full-step resolution.

The encoder position at the image trigger is stored in memory for possible later reference.

2.1.4.2   Encoder Trigger

This internal hardware module allows for the generation of triggers every K microsteps (see figure).
It allows to control the spacing of the scanlines with high resolution.

At very low encoder speed the encoder position may occasionally move slightly backwards. In this case there will be no trigger until the encoder reaches the next valid trigger position in forward direction.

Although the encoder trigger is internal, for the image acquisition it acts as like an 'external trigger'. Triggers may be lost during the image acquisition time.

At startup time the system is in an uncalibrated state. This state can also be re-entered when the program 'vcio' is called without the option '-R'. When the first ENC Z signal in positive direction occurs, the system is calibrated, i.e. the encoder position is set to zero plus the current microstep and the next trigger position is set as follows:

trigger position = microstep + trigger increment + trigger offset.

The re-entering done at 'vcio' is a pseudo-calibration like using the Z signal at this encoder position which is all that is necessary for systems without an ENC Z signal.

If the ENC Z signalling is active, each incoming ENC Z signal resets the encoder position counter to zero plus the current microstep, in contrast to the trigger position which is only reset at calibration time.

The encoder does not require an ENC Z signal. Such a system is called an uncalibrated system. It produces the trigger signals relative to a virtual zero which was set at the start of the system and can be set manually by calling 'vcio'.

For systems using the ENC Z signal the situation is similar up to the point where the ENC Z signal occurs. I.e. there may be a number of uncalibrated trigger impulses before the occurrence of the ENC Z signal. After the occurrence of the ENC Z signal the system is calibrated, i.e. the trigger impulses are relative to the absolute zero set by the ENC Z signal at calibration time.

The GPIO input signal 28 is provided indicating that a first ENC Z impulse has been detected.