Fluke Victoreen 451P Operator's Manual page 13

If the Model 451 displays the "CO" message, but there is no response at the terminal press the spacebar
twice.
If there is a problem getting the communications message (CO) to be displayed on the 451P:
1. Be sure the computer communication port is active.
2. The 451 communication transmitter/RCR pair is active when it detects a negative mark voltage at
the receiver input. (CO) shall appear on the 451 display.
3. Press space bar twice.
If there is still a problem, consult the Fluke Biomedical, Radiation Management Services Repair
Coordinator for further instructions.
Operation
2
Installation
2-3