Tdct Online Mode

Display of EPICS PVs
Writing to EPICS PVs
EPICS Environment

Tdct can connect to EPICS IOCs and display online data for EPICS PVs. If configured, it can also modify PVs in an IOC.

Online mode can be entered from any online enabled tab by selecting the Online >> Go Online menu. The Online menu is only visible if the currently selected tab is online enabled.

A Tab is on-line enabled
At the first attempt to enter online mode during a Tdct session, a dialog pops up for the user to confirm the EPICS ports. This is implemented as a safeguard to prevent writing inadvertently to a wrong IOC.

Display of EPICS PVs

In on-line mode, EPICS PVs are displayed the following way:


Writing to EPICS PVs

Writing to PVs must be enabled in the Tdct configuration file with the [options] write_to_ioc  directive.

On the property sheet for an EPICS record, the "edit" column next to the "value" column provides  text input fields or drop-down menus as appropriate for the field type. 

Note: selecting a new value from a drop-down menu or terminating a text input field with RETURN will immediately write the new value to the IOC.


EPICS Environment

The EPICS Channel Access ports can be configured in the Tdct configuration file with the [EPICS ports] directive.

If EPICS_CA_SERVER_PORT and EPICS_CA_REPEATER_PORT are defined as environment variables, they override the values from the configuration file.

If EPICS_CA_ADDR_LIST is defined as environment variable, it will be used in configuring the Channel Access context.

Before the first connect attempt of a Tdct Session, the ports need to be confirmed.