Agilent Technologies HP 1660E Series User Manual page 264

Logic Analyzer Reference
Probing
Maximum Probe Input Voltage
The maximum input voltage of each logic analyzer probe is 40 volts
peak.
Pod Thresholds
Logic analyzer pods have two preset thresholds and a user-definable
pod threshold. The two preset thresholds are ECL (-1.3 V) and TTL
(+1.5 V). The user-definable threshold can be set anywhere between -
6.0 volts and +6.0 volts in 0.05 volt increments.
All pod thresholds are set independently.
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