Keyboard and Displays

Protecting setpoints

Additional information regarding INET control is available in Chapter 5, Signal Output. Servicing may be required for one or more devices on the INET loop if communication cannot be established.

Protecting setpoints

The HP 5890 provides a keyboard lock feature to minimize possibility of stored setpoints being altered unintentionally. When the HP 5890 keyboard is locked, setpoint values (numeric values, A, B, OFF, and ON) may only be displayed; they cannot be altered. START and STOP remain functional, so runs may be started or stopped.

To lock instrument setpoints, first enter the key sequence:

CLEAR . - ENTER

Then press ON to lock the keyboard, or OFF to unlock the keyboard. Figure 2•5shows displays occurring during this process.

Figure 2-5

 

 

 

ACTUAL

SETPOINT

CALIB

AND

TEST

[0-0]

 

 

 

ACTUAL

SETPOINT

 

 

 

 

 

KEYBOARD

 

LOCK

ON

 

 

 

 

ACTUAL

SETPOINT

 

 

 

 

 

KEYBOARD

 

LOCK

OFF

 

 

 

 

 

 

Keyboard Lock Displays

38