BeamPos Manual
Status:
This information applies to BeamPos version 1.5.14.5, which will be the first release version of the program.
Contents:
- Overview
- Minimum injection delay (recycle time).
- Hardware descriptions.
- GPIB setup
- Multiplexer scan (parameters etc.)
Other links:
Overview
HP4195A analyzer has bug. Cannot be used presently (991201 jsn)
Minimum injection delays (recycle time)
There must be a minimum injection delay (recycle time) for the measure device to have time to complete the measurement.
These times are:
Measure device | Minimum injection delays (recycle time) |
Single Pickup measurement (standard ASTRID type) HP8753D Analyzer | 0.7 s |
Single Pickup measurement (standard ASTRID type) HP4195A Analyzer | 0.1 s |
Qpol shunt (standard ASTRID type, with
Single Pickup measurement) HP8753D Analyzer | 1.0 s |
Qpol shunt (standard ASTRID type, with
Single Pickup measurement) HP4195A Analyzer | 0.1 s |
GPIB setup
The program currently (ver. 1.5.14.5) supports the following analyzers:
Nr | Instrument | GPIB device name (not used) | Suggested GPIB adr | |
1 | HP 4195A | HP4195A | 30 | |
2 | HP 8753D | HP8753D | 15 |
Multiplexer scan (parameter descriptions etc.)
The multiplexer has an option to be scanned under hardware (G64 firmware) control. One defines a start and a stop pickup and a time per pickup (or rather a trigger spacing and a number of triggers per pickup). Scanning is enabled when the hardware input is high AND when the software bit is enabled. Scan start is when the last of the two is enabled. There are two output triggers, one is intended for measurement point triggering occuring with a spacing given by the TriggerSpacing parameter. The second output is occurring when the multiplexer start pickup is selected.
Intended use: The BeamPos program manages the setup of the multiplexer scan (start, stop, trigger spacing, number of triggers per pickup) and when ready (and operator asks for measurement) the the multiplexer scan bit is set active. Measurements are the timed externally by connecting a DAF controlled output (AST99PGE static bit 3) to the External Run In. This Daf-bit must then be set high in the Daf-file when multiplexer scanning (and thereby measurement) has to be done.
Timing: Pickup is changed every (TrigSpc+1) * TrigPls * 10 ms. A full cycle takes (TrigSpc+1) * TrigPls * Nr_of_pickups_in_scan * 10 ms. The jitter is +- 3-4 ms (sigma spread is ~1.5 ms). Minimum trigger spacing is 20 ms.
Multiplexer parameters: See here for a list and a description of parameters involved in scanning the multiplexers :
Trigger connections out of G821 (rack 18)
Connector label | Description |
Mux. Scan out 1 | low pulse output for each trigger (occurring at intervals given by (TrigSpc+1)*10 ms, jitter is +-4ms Intended for triggering each meas point (there are TrigPls triggers for each pickup). |
Mux. Scan out 2 | low pulse trigger occuring at each start of a mux scan (i.e. each time mux start is selected) Jitter is +-3ms |
Mux. Scan Run In | Enables the mux scanning (together with UEV1ast.scan). Mux scan is started (with mux start) at low->high pulse. Mux
scan is discontinued when input goes low again. Intended to be connected to AST99PGE static bit 3 (wSet = 2048) (output is locoated in rack 1) |
jsn 001115
Last Modified 14 January 2019