Randy wrote:


Any B & S or PLC (A-B SLC 500) experts out there???? I need to figure
out what the Solid state relays are there for. My guess is they were
trying to overcome some shortfall of the old Modicon PLC.

I won't call myself a Allen Bradley expert but I suspect that driving the solenoids
directly from the relatively weak relays or thyristors inside the slick is what they were
trying to avoid.

When I retrofited St. Lawrence hydraulic forming presses, every directional valve was
controlled by an auxilary relay switched by the PLC.

Wes