HP 8920B - Page 28

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Chapter 1, Using HP-IB
Getting Started
General HP-IB Programming Guidelines
The following guidelines should be considered when developing programs which
control the Test Set through HP-IB:
• Guideline #1. Avoid using the TX TEST and RX TEST screens.
The RX TEST and TX TEST screens are specifically designed for manual testing of
land mobile FM radios and, when displayed, automatically configure six “priority”
fields in the Test Set for this purpose. The priority fields and their preset values are
listed in table 1 on page 29. When the TX TEST screen or the RX TEST screen is dis-
played, certain priority fields are hidden and are not settable. The priority fields which
are hidden are listed in table 1 on page 29.
When the TX TEST screen or the RX TEST screen is displayed, any HP-IB commands
sent to the Test Set to change the value of a hidden priority field are ignored. Hidden pri-
ority fields on the TX TEST or RX TEST screens are not settable manually or program-
matically.
Displaying either of these screens automatically re-configures the 6 “priority” fields as
follows:
1. When entering the RX TEST screen,
a. the RF Generator’s Amplitude field, the AFGen1 To field and the AF An-
alyzer’s measurement field (measurement displayed in upper, right portion of
CRT display) are
• set to their preset values upon entering the screen for the first time since
power-up, OR
• set to their preset values if the PRESET key is selected, OR
• set to the last setting made while in the screen
b. the RF Generator Amplitude field and the AFGen1 To field are
• set to their preset values whenever entering the screen, OR
• set to their preset values if the PRESET key is selected