System Structure

The conveyor system configurations and trigger methods are as shown below.

	Trigger Method	Description
1	Hardware trigger	This method latches the camera image and encoder count using trigger signals from the robot controller I/O output. [Detection by vision only]
2	Hardware trigger	This method latches the camera image and encoder count using trigger signals from the photoelectric sensor output. [Detection by vision + sensor]
3	Software trigger	This method latches the camera image and encoder count using the command from the software (Epson RC+), without using trigger signal. A delay occurs compared to the hardware trigger due to the time it takes to process the command. [Detection by vision only]
4	Hardware trigger	This method latches the encoder count using the photoelectric sensor output. In the case of a sensor conveyor, the position is estimated based only on the workpiece identification output by a photoelectric sensor, without using a camera. (Because displacement cannot be detected in the width direction of the conveyor, a guide or other device is required to regulate any displacement in the width direction.) [Detection by sensor only]

There are hardware trigger and software trigger as trigger methods for latching the camera image and encoder count.

	Hardware trigger	Software trigger
Use cases	When high-precision picking is required When the conveyor speed is fast (Generally, a hardware trigger is recommended for conveyor tracking.)	When using conveyor tracking on a trial basis When the conveyor speed is slow
Overview	A configuration that latches via an external trigger signal from a photoelectric sensor, controller I/O, etc., synchronizing the camera image with the encoder count.	A configuration that latches the encoder count via the "Cnv_Trigger" software command, without using an external trigger.
Characteristics	Pros The timing can be adjusted with high precisions as a physical trigger signal is used to synchronize camera imaging and encoder counting, making it suitable for imaging moving workpieces. It is especially important to improve synchronization accuracy when the conveyor speed is high and displacement between the imaging and encoder latch timing can easily affect accuracy. Cons The trigger cable must be wired to the camera, PG board or Conveyor Tracking Option Kit B.	Pros Simple system configuration as no trigger signal wiring is required. Cons As the camera capture commands and the encoder count commands are issued separately in the SPEL sequence code, the camera capture timing and encoder latch timing vary according to the communication speed and the amount of vision processing calculations. This timing variation adversely affects the conveyor tracking accuracy.