Kindly do not use telnet to access the HV crates. The GUI is preferred, but there are other CLI methods to talk to the crate that will not generate problems for other users.
The HV system serves multiple groups and we don't need it stalling out because someone took a short cut using telnet and then left the serial connection in a non-standard mode...
I generated a Wiki with an entry on the HV control system as it is now. I encourage those with the knowledge to update/correct it with the appropriate detector maps.
https://hallaweb.jlab.org/wiki/index.php/HV_control_for_LHRS%2C_RHRS%2C_Beamline_crates