Interlock and Pressure Monitoring

Brief Description

This FESA-class will only be a temporary solution for the proton linac ion source test, to

• input interlock information
• read the vacuum pressure (ADC read)

The information (basically just some boolean value) is only passed to the operating-layer. No other MCS-class will require information from this class.

Read out will be done vie some ADC-Card in the SCU-Bus. The card provides both

• digital input (special implementation on the ADDA-card), since the proposed standard digital input card will not be available at time)
• two ADCs (plus two DACs, which will not be used in this FESA-class)

A modified ADDA-card will be used in this FESA-class for digital input, since the proposed standard digital input SCU card will not be available in time for the ion source test installation.

Property Layout

Name	FESA-Type	field / value-item	Value-Type	Unit	Description
Version	version				Default GSI field.
Status	status				Default GSI field.
Setting	setting				Default GSI field.
Reset	reset				Default GSI field.
Power	power				Default GSI field. Allways ON - it is not allowed to set the value to OFF (Exception).
Init	init				Default GSI field.
Acquisition	acquisition				Default GSI field.
InterlockStatus	acquisition	interlockStatus	int		The interlock status as a bit set encoded by the integer value. Each bit of the value represent the interlock status of the connected device.
VacuumPressure	acquisition	vacuumPressure	double	tbd	A placeholder value, since the field is currently not excaclty specified.

Technical Information

Name:	PlinacMonitorIO
SVN-Link:	https://www-acc.gsi.de/svn/fesa/device/class/PlinacMonitorIO
Deploy Unit Name:	PlinacMonitorIODeployUnit
SVN-Link:	https://www-acc.gsi.de/svn/fesa/device/deploy-unit/PlinacMonitorIODeployUnit
Current Version:	0.1.0
FESA Version:	0.8.1

Implementation Details

The implementation of this class is based on the following premises:

• Interlock status is transmitted by voltage signals from the device (hi voltage – OK, low voltage – Interlock)
• Vacuum pressure is transmitted by voltage signal (voltage ~ pressure)

This FESA class periodically reads the values from the AD-Card and saves them. The reading of the values is triggered by an RT-Event and is done using the etherbone Framework. Interlock signals are bit-wise interpreted and converted into a single integer value. Since only one such value is used, the class can currently handle up to 32 devices. Example: consider 2 devices plugged in for monitoring. In this case the possible range of interlock status will be 0..3. When both devices are operating normally then 3 is delivered (binary 011). If the first device reports an interlock that the value 2 (binary 010).

The measurement of the vacuum pressure isn’t fully specified yet. More information will follow soon.

ToDo

- Implement the connection to the AD-Card as soon as the HW it available