HP Codemaster 100 User Manual page 120

Preparing the Patient
The HP 12-Lead patient cable can only be used with snap ECG monitoring
NOTE
electrodes. Use only Hewlett-Packard approved ECG monitoring electrodes.
Do not mix reusable and disposable electrodes.
Be careful to correctly align the cable plug when connecting the patient ECG
leads cable to the HP CodeMaster 100. Correctly orient the cable plug key
with the connector slot. If the ECG leads cable falls out or is incorrectly
connected, the message LEADS OFF appears on the display.
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