I have an Allen Bradley ControlLogix 5550 system with a 1746-OB32 (PNP Sourcing) output card. Allen Bradley currently does not offer a sinking output card for this platform. The signal is used to synchronize external devices to master. The signal is roughly 3 Hz, 18 hours/day, or 194,400 pulses per day which would quickly exceed the life expectancy of dry contact relays I am familiar with. The last requirement is that the solid state relay be optically isolated. Any information would be greatly appreciated.