Access PVs to read, write, or subscribe to PV values. After you publish PVs to an EPICS network by using the EPICS Server I/O server, use EPICS Client I/O servers or third-party EPICS clients to access PVs.

Note Some third-party EPICS clients do not support all these three operations on PV values. Refer to the manuals of third-party EPICS clients for detailed information.

When you write values to a PV that corresponds to a Boolean shared variable, you must write True or False to this PV. Otherwise, the value of this PV does not change.

The following table shows the PV attributes that you can access for different PV categories:

PV Category PV Attribute Description
All VAL Displays the current value of the PV.
STAT Displays the current status of the PV.
SEVR Displays the current alarm severity of the PV.
Numeric HIHI Displays the HIHI alarm level of the PV.
HIGH Displays the HIGH alarm level of the PV.
LOW Displays the LOW alarm level of the PV.
LOLO Displays the LOLO alarm level of the PV.
HHSV Displays the severity of HIHI alarms.
HSV Displays the severity of HIGH alarms.
LSV Displays the severity of LOW alarms.
LLSV Displays the severity of LOLO alarms.
Logical OSV Displays the severity of ONE alarms.
ZSV Displays the severity of ZERO alarms.
Array NELM Displays the element number of the array.