This section describes what an AIDA-PVA user should know about accessing the SLC Magnet Data through AIDA-PVA. This data provider allows the retrieval of magnet primary/micro/unit names and secondary values for a specified display group, primary, and secondary. It also allows the setting of BDES/VDES values for specified magnet primary/micro/unit names and optionally performs either a trim or perturb operation. This set operation returns the state names and new BACT/VACT values. Finally, this data provider allows for the setting of BCON values for specified magnet primary/micro/unit names. For general information on using AIDA-PVA see Basic Users Guide to Aida, and the EPICS javadoc.

Summary

Obtains primary/micro/unit strings and secondary values.
Sets BDES/VDES/BCON values and optionally trim.

Synopsis

	PV	Arguments	Description
1.6.1	`<dgrp-mnemonic>:<primary>:<secondary>`	[ `MICROS` `UNITS` ]	Get secondary value
1.6.2	`MAGNETSET:BDES`	`VALUE` `MAGFUNC` [ `LIMITCHECK` ]	Set BDES value
	`MAGNETSET:VDES`	`VALUE` `MAGFUNC` [ `LIMITCHECK` ]	Set VDES value
1.6.3	`MAGNETSET:BCON`	`VALUE`	Set BCON value

1.6.1. Get Secondary Value

<display-group-mnemonic><primary>:<secondary>
- MICROS : range-of-micros
- UNITS : range-of-units

Obtains primary/micro/unit strings and secondary values for a specified display group, primary, and secondary name, with optional micro and unit range filters.

Arguments

Argument Names	Argument Values	Description
`MICROS`	`<start_micro>-<end_micro>`	This specifies a range of micro names of interest within the specified display group
`UNITS`	`<start_unit>-<end_unit>`	This specified a range of unit numbers of interest within the specified display group

Return value

TYPE	Return Column	Column Type	Description
`TABLE`	`name`	`STRING_ARRAY`	name of each magnet for specified display group and primary (optionally filtered by specified micro and unit ranges)
	`secondary`	`FLOAT_ARRAY`	secondary values (BDES or VDES)

Examples

Operations

DEV_DGRP:XCOR:BDES MICROS="LI31-LI31" UNITS="1-500"

Response

Magnet Name	secondary

`name`	`secondary`
XCOR:LI31:41	5.0
XCOR:LI31:201	0.0
XCOR:LI31:301	0.0
XCOR:LI31:401	0.03

1.6.2. Set BDES / VDES Value

MAGNETSET:BDES
- VALUE* : structure
  - NAMES* : list-of-magnet-names
  - VALUES* : list-of-values
- MAGFUNC* : trim-operation
  - TRIM
  - PTRB
  - NOFUNC
- LIMITCHECK : limit-check-behavior
  - ALL
  - SOME
MAGNETSET:VDES
- VALUE* : structure
  - NAMES* : list-of-magnet-names
  - VALUES* : list-of-values
- MAGFUNC* : trim-operation
  - TRIM
  - PTRB
  - NOFUNC
- LIMITCHECK : limit-check-behavior
  - ALL
  - SOME

Sets BDES/VDES values for specified primary/micro/unit name strings to specified values and optionally performs a specified operation (trim or perturb). This set operation returns the resulting state names and BACT/VACT values

Arguments

Argument Names	Argument Values	Description
`VALUE`*	`{ <names-array>, <values-array> }`	a structure containing congruent arrays for names and values
	`<names-array>`	an array of magnet names
	`<values-array>`	an array of set values
`MAGFUNC`*	`<trim-operation>`	Specifies trim operation
	`TRIM`	Perform a trim operation
	`PTRB`	Perform perturb operation
	`NOFUNC`	Perform neither a trim or perturb operation
`LIMITCHECK`	`<limit-check-behavior>`	Used to determine behavior when the set value for one or more devices is outside of its low/high limits. The default setting of this parameter is `ALL`.
	`ALL`	The entire request will fail resulting in an exception being thrown and no `BDES`/`VDES` values being set for any of the request devices
	`SOME`	The set value action will succeed for those set values that are within limits and will not be performed for those set values outside their limits (the state string return values for these devices will be set to the string "Outside Limits").

Return value

TYPE	Return Column	Column Type	Description
`TABLE`	`state`	`STRING_ARRAY`	string indicating the state of each specified magnet device. Set to blanks (checking that the first character is blank is all that is necessary) if the state is good. Set to the string "Outside Limits" if a set value is outside of its limits and the optional parameter LIMITCHECK is set to SOME
	`value`	`FLOAT_ARRAY`	`BACT`/`VACT` value for each device

Examples

Operations

‘MAGNETSET:BDES" MAGFUNC=TRIM VALUE=’{"names": [ "XCOR:LI31:41"], "values": [ 4.0 ] }<tt> -</tt>MAGNETSET:VDES" MAGFUNC=TRIM VALUE='{"names": [ "XCOR:LI31:41"], "values": [ 4.0 ] }`

Response

State	value

`state`	`value`
	5.0

1.6.3. Set BCON Value

MAGNETSET:BCON
- VALUE* : names-and-values

Sets specified BCON secondary values

Arguments

Argument Names	Argument Values	Description
`VALUE`*	`{ <names-array>, <values-array> }`	a structure containing congruent arrays for names and values
	`<names-array>`	an array of magnet names
	`<values-array>`	an array of set values

Return value

None

Examples

operation
‘MAGNETSET:BCON VALUE=’{"names": [ "XCOR:LI31:41"], "values": [ 5.0 ] }`

CLI and Code Examples

Commandline Examples

example type

example

pvcall

pvcall "DEV_DGRP:XCOR:BDES" MICROS="LI31-LI31" UNITS="1-100"

pvcall "MAGNETSET:BDES" MAGFUNC=TRIM VALUE='{"names": [ "XCOR:LI31:41"], "values": [ 4.0 ] }'

pvcall "MAGNETSET:BCON" VALUE='{"names": [ "XCOR:LI31:41"], "values": [ 5.0 ] }'

eget

eget -s DEV_DGRP:XCOR:BDES -a MICROS 'LI31-LI31' -a UNITS '1-100'

eget -s MAGNETSET:BDES -a MAGFUNC TRIM -a VALUE '{"names": [ "XCOR:LI31:41"], "values": [ 4.0 ] }'

eget -s MAGNETSET:BCON -a VALUE '{"names": [ "XCOR:LI31:41"], "values": [ 5.0 ] }'

Matlab Examples

Note: For general details about accessing AIDA-PVA from matlab see User Guide for Matlab Users

action

example

Get

try
    builder = pvaRequest('DEV_DGRP:XCOR:BDES');
    builder.with('MICROS', 'LI31-LI31');
    builder.with('UNITS', '1-100');
    table = ML(builder.get());
    labels = table.labels
    names = table.values.name
    values = table.values.secondary
catch e
    handleExceptions(e);
end
 
labels =
    'name of magnet'    'secondary values'
 
names =
    'XCOR:LI31:41'
 
values =
     4

Set

try
    builder = pvaRequest('MAGNETSET:BDES');
    builder.with('MAGFUNC', 'NOFUNC');
    jstruct = AidaPvaStruct();
    jstruct.put('names', { 'XCOR:LI31:41'});
    jstruct.put('values', { 4.0 } );
    mstruct= ML(builder.set(jstruct))
    mstruct.values.status(1)
    mstruct.values.bact_vact(1)
catch e
    handleExceptions(e);
end
 
mstruct =
            size: 1
          labels: {'status'  'bact/vact'}
           units: []
    descriptions: []
      fieldnames: {'status'  'bact_vact'}
          values: [1x1 struct]
 
ans =
    'OUTOFTOL '
 
ans =
    0.2983          

try
    builder = pvaRequest('MAGNETSET:BCON');
    jstruct = AidaPvaStruct();
    jstruct.put('names', { 'XCOR:LI31:41'});
    jstruct.put('values', { 5.0 } );
    builder.set(jstruct);
catch e
    handleExceptions(e);
end

Java Examples

example type

example

AidaPvaClient

import edu.stanford.slac.aida.client.PvaTable;
import org.epics.pvaccess.server.rpc.RPCRequestException;
 
import java.util.List;
import java.util.Map;
 
import static edu.stanford.slac.aida.client.AidaPvaClientUtils.pvaRequest;
 
public class Example {
    public PvaTable getValues() throws RPCRequestException {
        return (PvaTable) pvaRequest("DEV_DGRP:XCOR:BDES")
                .with("MICROS", "LI31-LI31")
                .with("UNITS", "1-100")
                .get();
    }
 
    public PvaTable setValues(List<String> names, List<Float> values) throws RPCRequestException {
        return (PvaTable) pvaRequest("MAGNETSET:BDES")
                .with("MAGFUNC", "TRIM")
                .set(Map.of("names", names, "values", values));
    }
 
    public void setBconValues(List<String> names, List<Float> values) throws RPCRequestException {
        pvaRequest("MAGNETSET:BCON").set(Map.of("names", names, "values", values));
    }
}

PvaClient

import org.epics.nt.NTURI;
import org.epics.pvaClient.PvaClient;
import org.epics.pvaClient.PvaClientChannel;
import org.epics.pvaccess.server.rpc.RPCRequestException;
import org.epics.pvdata.pv.PVStructure;
 
import java.util.List;
 
public class Example {
    public PVStructure getValues() throws RPCRequestException {
        String pvName = "DEV_DGRP:XCOR:BDES";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("micros")
                .addQueryString("units")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("micros").put("LI31-LI31");
        uri.getQuery().getStringField("units").put("1-100");
 
        PvaClient client = PvaClient.get("pva");
        PvaClientChannel channel = client.createChannel(pvName);
        return channel.rpc(uri.getPVStructure());
    }
 
    public PVStructure setValues() throws RPCRequestException {
        String pvName = "MAGNETSET:BDES";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("magfunc")
                .addQueryString("value")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("magfunc").put("TRIM");
        uri.getQuery().getStringField("value").put("{\"names\": [ \"XCOR:LI31:41\"], \"values\": [ 4.0 ] }");
 
        PvaClient client = PvaClient.get("pva");
        PvaClientChannel channel = client.createChannel(pvName);
        return channel.rpc(uri.getPVStructure());
    }
 
    public void setBconValues(List<String> names, List<Float> values) throws RPCRequestException {
        String pvName = "MAGNETSET:BCON";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("value")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("value").put("{\"names\": [ \"XCOR:LI31:41\"], \"values\": [ 5.0 ] }");
 
        PvaClient client = PvaClient.get("pva");
        PvaClientChannel channel = client.createChannel(pvName);
        channel.rpc(uri.getPVStructure());
    }
}

PvAccess

import org.epics.nt.NTURI;
import org.epics.pvaccess.client.rpc.RPCClientImpl;
import org.epics.pvaccess.server.rpc.RPCRequestException;
import org.epics.pvdata.pv.PVStructure;
 
import java.util.List;
 
public class Example {
    public PVStructure getValues() throws RPCRequestException {
        String pvName = "DEV_DGRP:XCOR:BDES";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("micros")
                .addQueryString("units")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("micros").put("LI31-LI31");
        uri.getQuery().getStringField("units").put("1-100");
 
        RPCClientImpl client = new RPCClientImpl(pvName);
        PVStructure response = client.request(uri.getPVStructure(), 3.0);
        client.destroy();
        return response;
    }
 
    public PVStructure setValues() throws RPCRequestException {
        String pvName = "MAGNETSET:BDES";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("magfunc")
                .addQueryString("value")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("magfunc").put("TRIM");
        uri.getQuery().getStringField("value").put("{\"names\": [ \"XCOR:LI31:41\"], \"values\": [ 4.0 ] }");
 
        RPCClientImpl client = new RPCClientImpl(pvName);
        PVStructure response = client.request(uri.getPVStructure(), 3.0);
        client.destroy();
        return response;
    }
 
    public void setBconValues(List<String> names, List<Float> values) throws RPCRequestException {
        String pvName = "MAGNETSET:BCON";
 
        NTURI uri = NTURI.createBuilder()
                .addQueryString("value")
                .create();
        uri.getPath().put(pvName);
        uri.getQuery().getStringField("value").put("{\"names\": [ \"XCOR:LI31:41\"], \"values\": [ 5.0 ] }");
 
        RPCClientImpl client = new RPCClientImpl(pvName);
        client.request(uri.getPVStructure(), 3.0);
        client.destroy();
    }
}