These modules have 16 relays with inputs located on rear panel header connectors and outputs bussed on the motherboard. The G-2S has 2 Pole, Type S relays, two 20 pin headers (requires signal I/O mod and limits mainframe to 15 switch modules).
$580.00
32 Wire Signal I/O Module with two H20RT Connectors
1 Pole, Type S relays, two 20 pin headers, requires signal I/O mod and limits mainframe to 15 switch modules
2 Pole, High Voltage (BE) relays, choose connectors and configuration
256 channel Mainframe, holds up to 16 switch modules in a matrix configuration or 15 with the general series. Price includes 16 LED Display Modules. Switch Modules are priced separately.