ECM P/N 5041 provides eight channels of RS485 / RS422 I/O with fixed 120 ohm termination for each channel. Speeds are up to 30M bits per second. All channels power up as inputs. Also transceiver inputs are always enabled for loop back diagnostic use when the outputs are enabled. Software can enable outputs on a channel by channel basis.

In the example shown a Technobox P/N 4988 breakout panel provide two 9 pin d-sub connections for the RS485/422 ports. Each 9 pin d-sub carries four RX/TX pairs and a ground. Note that a pair  of the Technobox P/N 4988 breakout panel ports is in use, allowing other ECMs to use the remaining 6 pin d-sub connections. A serial identification circuit prevents use with incorrect FPGA IP. Other RS422/485 usages include military, medical, transportation and industrial control systems.

Datasheet http://www.technobox.com/Datasheet-ECM-5041-Interface-4pgv1-A80401-press.pdf

micro mezzanine system electrical conversion module RS485 / RS422 8 channels programmable termination Technobox 5041