Experimental Physics and
Industrial Control System

Mark Rivers via Tech-talk <[email protected]> · Wed, 20 Nov 2019 01:48:26 +0000

Hi Michael,

One solution is to implement the drvUserCreate() method in your driver.

drvUserCreate can call the getAddress() method to get the address of this device from the pasynUser passed to it.  You can then build an std::set of the addresses that are actually used.  You only insert a new address into the set if std::set.find() does not find the address in the set already.  Once you call getAddress() you then call the base class asynPortDriver::drvUserCreate() to complete the operation.

Your driver can then loop over the entries in the std::set.

Mark

________________________________
From: Tech-talk <[email protected]> on behalf of Dunning, Michael via Tech-talk <[email protected]>
Sent: Tuesday, November 19, 2019 4:02 PM
To: EPICS Tech-Talk
Subject: asynPortDriver: get all addresses for ASYN_MULTIDEVICE

I've written an asynPortDriver for a TCP/IP-to-BitBus gateway which talks to power supply controllers.  The driver sends addressed messages to each controller and receives similar messages as responses.  The controllers may have non-sequential addresses in the [1, 200] range.

It works well with a single controller, and now I'm adding support for multiple controllers.  Since the gateway doesn't support multiple sockets, I'm using ASYN_MULTIDEVICE (multiple addresses using a single asyn port).

To poll the controllers, I need to loop over all addresses in my driver.  If I have sequential addresses that's easy, but mine may be non-sequential and I don't want to loop over non-existent addresses.
Is there a way to get a list of all registered addresses for a given port from asynManager somehow?  By "registered" I mean an address that's present in a record and tied to a specific port, e.g.:

record(bo, "$(ps):StateSetpt") {
    field(DESC, "Power Supply On/Off")
    field(DTYP, "asynInt32")
    field(OUT,  "@asyn($(asynPort), $(address), 0) STATE_SETPT")
    field(ZNAM, "OFF")
    field(ONAM, "ON")
}

My first attempt would be to follow the asynReport (pasynManager->report) function which sets up a linked list and prints all addresses.  Am I on the right track?  Or is there something built-in that I missed?

Thanks,
Mike

Michael Dunning
SLAC National Accelerator Laboratory
2575 Sand Hill Road
Menlo Park, CA 94025
(650) 926-5200

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System