Difference between revisions of "EPICS Cheat Sheet"

Latest revision as of 16:17, 17 March 2023

Channel Access command-lines

Channel Access (CA) allows users to interact with Process Variables (PV):

caget - get the value of one of more PVs

caput - change the value of a PV

camonitor - monitor the value of one or more PVs

cainfo - print info about a PV, including which host is running the IOC

Example:

$ caget kmp3:m1.VAL
kmp3:m1.VAL            60
$ caget kmp3:m1.{DESC,RTYP,DTYP}
kmp3:m1.DESC           theta motor
kmp3:m1.RTYP           motor
kmp3:m1.DTYP           asynMotor

Noteworthy fields

A Process Variable (PV) is a the field from a record:

PV = record_name + . + field_name

Most common fields:

VAL - the default field (used if no field is specified in the vast majority of cases)

SCAN - determines when a record processes

NAME - the record name (helpful if records are aliased)

DESC - record description

RTYP - the record type

DTYP - the device support type (not meaningful for all record types)

DISP - disable puts (ca = channel access & pva = pv access) from outside the IOC (when non-zero); e.g. disable a motor from the motorx_all screen

DISV/DISA/SDIS - disable record processing internally

Record processing is disabled when DISA equals DISV (e.g. uses SDIS field to read in a value/mode, which will disable some control if a certain mode is active)
DISA is set to the value of the PV in the SDIS field, if it isn't empty

TPRO - trace processing: when set to 1 prints out all the records that get processed after the record is processed; used only for troubleshooting

Note: some of the fields of a record are actually record attributes (they return the same value for all instances of the record type; see https://epics.anl.gov/)

IOC shell commands

To connect to (disconnect from) the IOC shell, see here:

help [command] - shows available commands or syntax of specified command

dbpr record_name [0-9] - displays fields and values for a given record

dbl - lists all records in an IOC

dbl record_type - lists all records of a specific type in an IOC

dbl record_type "field_list" - lists specified fields (space-separated list) of records of a specific type in an IOC

dbpf pv_name value - change a PV’s value – analogous to caput

dbgf pv_name - read a PV’s value – analogous to caget

epicsEnvShow - prints environment variables

seqShow - shows running sequence programs

seqStop - stops a running sequence program

Links

[EPICS 101]
[IOC 101]

@@ Line 1: / Line 1: @@
-== Channel Access (CA) command-lines ==
+== Channel Access command-lines ==
-* <code>'''caget'''</code> - get the value of one of more PVs
+Channel Access (CA) allows users to interact with Process Variables (PV):
-* <code>'''caput'''</code> - change the value of a PV
-* <code>'''camonitor'''</code> - monitor the value of one or more PVs
+:<code>'''caget'''</code> - get the value of one of more PVs
-* <code>'''cainfo'''</code> - print info about a PV, including which host is running the IOC
+:<code>'''caput'''</code> - change the value of a PV
+:<code>'''camonitor'''</code> - monitor the value of one or more PVs
+:<code>'''cainfo'''</code> - print info about a PV, including which host is running the IOC
 Example:
-  $ caget kmp3:m1.{DESC,RTYP,DTYP,VAL}
+ $ caget kmp3:m1.VAL
+ kmp3:m1.VAL            60
+  $ caget kmp3:m1.{DESC,RTYP,DTYP}
   kmp3:m1.DESC           theta motor
   kmp3:m1.RTYP           motor
   kmp3:m1.DTYP           asynMotor
- kmp3:m1.VAL            60
+== Noteworthy fields ==
+A Process Variable (PV) is a the field from a record:
+::<code>PV = record_name + . + field_name''</code>
+Most common fields:
+:<code>'''VAL'''</code> - the default field (used if no field is specified in the vast majority of cases)
+:<code>'''SCAN'''</code> - determines when a record processes
+:<code>'''NAME'''</code> - the record name (helpful if records are aliased)
+:<code>'''DESC'''</code> - record description
+:<code>'''RTYP'''</code> - the record type
+:<code>'''DTYP'''</code> - the device support type (not meaningful for all record types)
+:<code>'''DISP'''</code> - disable puts (ca = channel access & pva = pv access) from outside the IOC (when non-zero); e.g. disable a motor from the motorx_all screen
+:<code>'''DISV/DISA/SDIS'''</code> - disable record processing internally
+:*Record processing is disabled when <code>'''DISA'''</code> equals <code>'''DISV'''</code> (e.g. uses SDIS field to read in a value/mode, which will disable some control if a certain mode is active)
+:*<code>'''DISA'''</code> is set to the value of the PV in the <code>'''SDIS'''</code> field, if it isn't empty
+:<code>'''TPRO'''</code> - trace processing: when set to 1 prints out all the records that get processed after the record is processed; used only for troubleshooting
+<u>Note</u>: some of the fields of a record are actually record attributes (they return the same value for all instances of the record type; see [https://epics.anl.gov/base/R3-16/2-docs/AppDevGuide/DatabaseDefinition.html#x7-2630006.6 https://epics.anl.gov/])
 == IOC shell commands ==
+To connect to (disconnect from) the IOC shell, see [https://wiki-ext.aps.anl.gov/blc/index.php?title=IOC_101#Connecting_to_an_IOC.E2.80.99s_shell here]:
 :'''<code>help [command]</code>''' - shows available commands or syntax of specified command
 :'''<code>dbpr record_name [0-9]</code>''' - displays fields and values for a given record
@@ Line 27: / Line 52: @@
 :'''<code>seqShow</code>''' - shows running sequence programs
 :'''<code>seqStop</code>''' - stops a running sequence program
+== Links ==
+* [[https://wiki-ext.aps.anl.gov/blc/index.php?title=EPICS_101 EPICS 101]]
+* [[https://wiki-ext.aps.anl.gov/blc/index.php?title=IOC_101 IOC 101]]

Difference between revisions of "EPICS Cheat Sheet"

Latest revision as of 16:17, 17 March 2023

Contents

Channel Access command-lines

Noteworthy fields

IOC shell commands

Links

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