Connect to real IOCs

bobview uses the standard EPICS client variables (see Environment variables).

Search by UDP

Name the hosts (or broadcast addresses) to search:

EPICS_CA_ADDR_LIST="ioc1.example.com 10.0.0.255" bobview screen.bob
EPICS_PVA_ADDR_LIST=10.0.0.255 bobview screen.bob

Go through a gateway over TCP

When UDP search can't reach the IOCs, for example from a phone's Linux Terminal VM behind NAT, name a gateway reached over TCP. This works through NAT since the phone opens the connection:

EPICS_CA_NAME_SERVERS=gateway.example.com:9064 bobview screen.bob
EPICS_PVA_NAME_SERVERS=gateway.example.com:5075 bobview screen.bob

The example-services ca-gateway listens on port 9064 of its host.

Choose the protocol

PV names prefixed pva:// use PV Access; those with no prefix, or ca://, use Channel Access. The other prefixes are in Macros, rules and PV types.

Check a PV without the viewer

bobview-probe prints live values from the command line, and can write:

bobview-probe bl01t:SUM pva://bl01t:A
bobview-probe --seconds 10 --put bl01t:A=3.5 bl01t:SUM

Watch only, never write

Start the viewer with --read-only to refuse every write (see Writes and safety):

bobview --read-only screen.bob

For more output while diagnosing a connection, set BOBVIEW_LOG=debug.