The HP 87130A attenuator/switchdriver is an HP-IB compatible instrument  designed to drive electromechanical switches and stepattenuators.

• The standard instrument has a single internal driver board capable of driving up to 31 SPDT switches, or combinations of SPDT and multithrow switches.

• The HP87130 Aattenuator/switch driver may be externally connected to  a maximum of seven HP 84940A driver boards and can control and sense switching for up to 248 switches.