Hengstler Signo 721.2 User Manual page 161

10 Malfunctions
Overview of Errors
Error
Display remains dark
Counter does not count
Incorrect counting
Possible cause
Machine/plant not powered on
Defective voltage supply
Defective signal generator;
Counter does not receive any counting signals
Adjusted to incorrect mode of operation (F1)
Single-channel, directional input, differential counting,
phase discriminator
Incorrect adjustment of PNP/NPN logic and input level
(F3)
High-level does not exceed the upper amplitude
threshold; low-level does not fall below the lower ampli-
tude threshold
Continuous reset signal is applied
Continuous gate signal is applied
161
To be corrected by:
Operator
Qualified electrician
Skilled personnel
Skilled personnel
Skilled personnel
Qualified electrician
Qualified electrician
Qualified
electrician