The SN74FB2031 device is a 9-bit transceiver designed to translate signals between TTL and backplane transceiver logic (BTL) environments. It is specifically designed to be compatible with IEEE Std 1194.1-1991. The B port operates at BTL-signal levels. The open-collector B ports are specified to sink 100 mA. Two output enables (OEB and OEB) are provided for the B outputs. When OEB is low, OEB is high, or VCC is less than 2.1 V, the B port is turned off.