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
Status	status				Default GSI field.
Power	power				Default GSI field. Allways ON - it is not allowed to set the value to OFF (Exception).
Reset	reset				Default GSI field.
Init	init				Default GSI field.
Version	version				Default GSI field.
Setting	setting				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