Schweitzer Engineering Laboratories SEL-751 - Page 468

7.18
SEL-751 Relay Instruction Manual Date Code 20170927
Communications
Communications Protocols
This is referred to as Access Level 0. Only a few commands are available at
Access Level 0. One is the ACC command. See the SEL-751 Relay Command
Summary at the end of this manual. Enter the ACC command at the Access
Level 0 prompt:
The ACC command takes the SEL-751 to Access Level 1. See Access
Commands (ACCESS, 2ACCESS, and CAL) on page 7.20 for more detail.
Access Level 1
When the SEL-751 is in Access Level 1, the relay sends the following prompt:
See the SEL-751 Relay Command Summary at the end of this manual for the
commands available from Access Level 1. The relay can go to Access Level 2
from this level.
The 2AC command places the relay in Access Level 2. See Access Commands
(ACCESS, 2ACCESS, and CAL) for more detail. Enter the 2AC command at
the Access Level 1 prompt:
Access Level 2
When the relay is in Access Level 2, the SEL-751 sends the prompt:
See the SEL-751 Relay Command Summary at the end of this manual for the
commands available from Access Level 2.
Any of the Access Level 1 commands are also available in Access Level 2.
Access Level C
The CAL access level is for use exclusively by the SEL factory and SEL field
service personnel to diagnose troublesome installations. A list of commands
available at the CAL level is available from SEL upon request. Do not enter
the CAL access level except as directed by SEL.
The CAL command allows the relay to go to Access Level C (see SEL-751
Relay Command Summary). Enter the CAL command at the Access Level 2
prompt:
=ACC <Enter>
=>
=>2AC <Enter>
=>>
=>>CAL <Enter>