6-10
Section 6: 9100 System Operation — SCPI Language
Final Width = 215mm
6.4.2
Operation via the IEEE-488 Interface
6.4.2.1
General
The power-up sequence is performed as in local operation. The 9100 can be programmed
to generate an SRQ at power-up, also preparing a status response for transmission to the
controller when interrogated by a subsequent serial poll.
6.4.2.2
Operating Conditions
When the 9100 is operating under the direction of the application program, there are two
main conditions, depending on whether the application program has set the 'REN'
management line 'true' or 'false':
1. REN True ('REN' line low):
The 9100 can be addressed and commanded if in either 'Manual' or 'Calibration' mode.
All access to front panel control will be removed, except for the bottom right screen
key, labelled 'Enable Local Usage'. The cursor controls will not be present.
If LLO (Local Lockout) has been sent with REN true, then the 'Enable Local Usage'
screen key will be inoperative. If LLO has not been sent, the 'Enable Local Usage'
screen key will return to local control as if REN were false (see 2 below).
The 9100 will act in response to valid commands, performing any changes in output,
etc. The display presentation will track the changes.
Remote control cannot command 'Configuration' mode or 'Procedure' mode. These
are Local Modes only. Remote control cannot break into locally-entered 'Configuration'
mode, 'Procedure' mode or 'Test' mode. However, 'Test' can be run remotely.
2. REN False ('REN' line high):
The 9100 will remain in Local Operation, but can be addressed and commanded,
while full access to front panel control is also retained.
The 9100 will act in response to the commands, performing any changes in output, etc.
These changes will occur rapidly enough for the only noticeable effect to be the
display presentation tracking the changes.
6.4.2.3
Programmed Transfer to Local Control (GTL or REN False)
The application program can switch the 9100 into ‘Local’ Control (by sending Command
GTL, or by setting the REN line false), permitting a user to take manual control from the
front panel.
The application program can regain ‘Remote’ control by sending the overriding command:
Listen Address with REN true (addressing the 9100 as a listener with the Remote Enable
management line true {Low}). This will re-impose remote control, unless the 9100 is in
Configuration, Procedure or Test Mode.