Two multifunction I/O modules feature both digital I/O and counter/timer functions on a single PMC module. The PMC424 provides 40 digital I/O channels for transistor-transistor logic (TTL) and differential signals plus four 16-bit counter/timers. The PMC464 has 64 TTL digital I/O and four counter/timers. Digital I/O are bidirectional for flexibility to meet almost any I/O configuration. Counter/timers can be used for counting events, generating waveform control signals, measuring waveforms, and other process monitoring operations. Six operating modes support a variety of functions. The PMC464 and PMC424 cost $600 and $700 each, respectively.