The GX5642 provides 128 digital Inputs or Outputs with direction control. The figure below shows a typical I/O channel block diagram when the board is in Software Controlled mode:
Typical I/O Channel
Under software controlled each channel can be programmed to operate in Conversion mode or Static I/O mode. All channels have two ports: TTL and Differential and each port can be programmed to be input or output depending on the channel’s programmed operation mode. Each channel’s output enable is controlled though software in both Conversion and Static I/O modes. Each channel’s port can be read back in both Conversion and Static I/O modes.
When a channel is programmed to Conversion mode the channel’s conversion direction can be programmed to be Differential to TTL (Differential port is input and TTL port is output) or TTL to Differential (TTL port is input and Differential port is output).
When a channel is programmed to Static I/O mode each of the channel’s ports can be set independently from the other, i.e. the TTL port operates separately from the Differential port. In this mode the channel’s TTL port can be set as input TTL or output TTL. And the channel’s Differential port can be set as input Differential or output Differential. The Differential I/O terminals are terminated with a built-in 100-Ohm resistor.