IDEC DATAVS2 Series - Manual (Page 68)

SVS2 Series Instruction Manual
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10.2. Inspection selection through Digital Input
To select the current inspection running on SVS a digital input with a special protocol is used.
The protocol is composed of a prologue followed by an epilogue.
Basically the prologue is composed of 3 pulses with a width of 10-100 ms and a duty cycle of 50 % .
The first pulse start the prologue window that last a max of Y=6*X+delta ms (where X is the selected
pulse width and delta is a 10 ms margin), during the prologue window 3 pulses are expected to start
the inspection selection window, when the prologue window is ended, if 3 and only 3 pulses were
counted we proceed to the next step, inspection selection pulse count.
A Y=16*X+delta ms time window is started and during this period pulses are counted (where X is the
selected pulse width and delta is a 10 ms margin).
At the end of the period, the counted pulses means the selected inspection (if the number fits in the
available inspections slots, otherwise the request is discarded).
The following image shows an oscilloscope picture that represent the selection of the inspection 8 by
the digital input as could be generated by a PLC.
Selection of the inspection number 8
In order to change pulses width accepted by the sensor during Inspection selection through digital
input handshake, you have to use the SVS Settings dialog window.
When connected to the sensor, from the Menu Sensor select item Change Inspection: