Gray Simulator - Version 1.7 Gray Simulator is OPC Server that can be usefull in OPC Clients debugging. Gray Simulator provides a set of various OPC tags: harmonic waves; triangle waves; square waves; ramps; random numbers and logical variables; random strings; random dates; enumerations; storage registers of different types. This OPC simulator is fully compliant with OPC Data Access 1.00, 2.05a and 3.00.