The HP 11713 A
Attenuator/Switch Driver has all of the necessary features to provide HP-IB control of up to two programmable attenuators of the HP 8494/5/6/7 or HP 33320/21/22//23 series and concurrently up to two electro-mechanical switches (e.g. HP 8761 B or 33311 series).
A local mode and front panel push buttons allow switches and attenuator sections to be operated manually (switching time less than 10 ms).
It can also be used to supply +24 V common and ten pairs of transistor switches to control up to 10 relays.
Output voltage for attenuator/switch 24 V.
Please find a corresponding data sheet here.