Switching Relays - Keithley 199 Instruction Manual

PRINCIPLES OF OPERATION
At power up, the Q output of Ul goes high, disabling the
outputs of U2. When the first !STROBE pulse comes along,
the D-type flip-flop in UI is cleared, enabling the U2 out-
puts, and normal relay operation can commence, depen-
ding on channel control data.
5.8.2 Switching Relays
Each of the eight input channels has a DPST (double-pole,
single-throw) relay associated with it in order to switch the
HI and LO terminals separately. The relays are connected
in two four-unit groups for maximum versatility in pole
switching. Relays Kl through K4 are associated with out-
put A, while relays K5 through KS ati connected to out-
put B. For 2-pole operations, the user must strap the two
outputs together (HI to HI, LQ to LO), while the outputs
must be connected separately for 4-pole operation.