Experimental Physics and
Industrial Control System

Vladis Korobov <[email protected]> · Tue, 6 Nov 2001 12:04:22 +0100 (MET)

Hi all,

I work with 2-processor configuration (the master is mvme167, the slave is
mvme162, see the drawing). The master is booted via Ethernet, the slave does via
Shared Memory network.

  boot Ethernet
-----+--------------
     |
  ---+----    --------
  |  ei  |    |      |   | PLC network
  |      |    | Slave|   |
  |Master|    | VME  |   |
  | VME  |    |    ei+---+
  |      |    |      |   |
  |      |    |      |   |
  |  sm  |    |  sm  |   |
  ----+---    ----+---
      |           |
 -----+-----------+----
 Shared Memory network

The master is currently used only to provide for the slave second
network interface. On the slave "sm" interface is used for booting and EPICS
downloading. The Ethernet port of the slave is connected to a PLC network
(physically separated from the boot network). After EPICS initialization
the special task attaches the second ("ei") interface to communicate with PLCs
and then connects to one or several PLCs to exchange data. There are devSup
and drvSup modules which represent these data to EPICS and vice versa.
   If CA clients (for example, MEDM screen) connected before the second
interface was attached all is OK. I can get and put PVs from MEDM screen.
But if I close this screen and then try to open it again after "ei" interface
already attached, I can't access anymore the PVs. The same for the telnet
connection to the slave and 'caget' and 'caput' requests.
   Is it possible anyhow to coexist for both of these interfaces and not to
interfere with each other: for CA connections to go always via "sm" interface
and for the PLC's ones only via "ei" interface? Or this is impossible,
and the last attached interface becomes the master?

Thank You in advance,
   V.Korobov

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System