ZOLL PD 2000 - Page 76

FUNCTIONAL DESCRIPTION
Outputs
The signal LEADOFF is sent from U10 to the CPU when the pace current
times the patient resistance exceeds about 300V + 15%. This is used to
detect Pacing leads off.
The pace pulse output goes to the pacer output connector on the paddles
set or to the Multi-Function Cable.
Independent safety monitoring is provided by the EPU. An independent
measure of pacing current is provided in the signal VSNS. It is derived
from a second current sensing transformer T2 and op amp U8. In Pace
mode VSNS must indicate the selected pacing current. If the expected
condition is not reached, the EPU stops the PWM controller and removes
+12 volts by way of XSAFE.
IV-17