Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Thu, 13 Jul 2006 09:41:23 +0200

Hello,
StreamDevice can do this quite simply:
Have several ai records, SCAN="I/O Intr".
Use a protocol like this: read_value { in "\$1%f"; }
Use in the INP link the protocol with a parameter: e.g. read_value(2)
No C-coding needed for this.
See: http://epics.web.psi.ch/software/streamdevice
Dirk
Jiro Fujita wrote:

Hello,
This is probably really an elementary question, but we have been
trying to interface an RS-232 device to EPICS soft IOC on Linux.  We
are using EPICS 3.14.8.2 with Asyn 4.6 (devGpib) via serial port.  The
response from the device looks like this:
1+32.23
2-50.01
3+23.98
...
...
It has five channels, reads one value a second, contiunally sending
the message through the serial port (that seems to be a typical thing
here at STAR/BNL).
We need to have the data sorted into five different PVs, based upon
the channel names.  In the end, the example above should look like
this:
channel 1: 32.23
channel 2: -50.01
channel 3: 23.98
Because we need the channel number and the + or - sign in the raw
data, I am taking the data into the IOC as string, having the
sequencer split the channel number, based upon that, we are trying to
put the value into the database.
Well, so far, we have not been successful in writing the sequencer
code.  To the best of my knowledge, the sequencer cannot manipulat
text strings, we are escaping all of that to C within the sequencer
code, but we are getting a number of errors upon make.
Here is the error message we are getting:
make[3]: Entering directory

`/home/sysuser/epics3.14.8.2/hygrometerApp/hygrometerApp/src/O.linux-x86'

/usr/bin/gcc -c -D_POSIX_C_SOURCE=199506L -D_POSIX_THREADS

-D_XOPEN_SOURCE=500 -D_X86_ -DUNIX -D_BSD_SOURCE -Dlinux

-D_REENTRANT -ansi -O3 -Wall -g -I. -I..

-I../../../include/os/Linux -I../../../include

-I/home/sysuser/epics3.14.8.2/base-3.14.8.2/../modules/soft/seq-2.0.11/include/os/Linux 
-I/home/sysuser/epics3.14.8.2/base-3.14.8.2/../modules/soft/seq-2.0.11/include 
-I/home/sysuser/epics3.14.8.2/base-3.14.8.2/include/os/Linux

-I/home/sysuser/epics3.14.8.2/base-3.14.8.2/include

-I/home/sysuser/epics3.14.8.2/modules/soft/asyn/4-6/include/os/Linux

-I/home/sysuser/epics3.14.8.2/modules/soft/asyn/4-6/include

sncProgram.c

../sncExample.stt:34: warning: type defaults to `int' in declaration of
`rob'

../sncExample.stt:34: conflicting types for `rob'

../sncExample.stt:9: previous declaration of `rob'

../sncExample.stt:35: `roba' undeclared here (not in a function)

../sncExample.stt:35: syntax error before "v"

../sncExample.stt:36: warning: type defaults to `int' in declaration of
`wa1'

../sncExample.stt:36: conflicting types for `wa1'

../sncExample.stt:29: previous declaration of `wa1'

../sncExample.stt:36: braced-group within expression allowed only

inside a function

../sncExample.stt:36: syntax error before string constant

../sncExample.stt:37: warning: type defaults to `int' in declaration of `z'

../sncExample.stt:37: initializer element is not constant

../sncExample.stt:37: warning: data definition has no type or storage class

make[3]: *** [sncProgram.o] Error 1

make[3]: Leaving directory

`/home/sysuser/epics3.14.8.2/hygrometerApp/hygrometerApp/src/O.linux-x86'
and here is the code:
program snchygrometer
%%#include <ctype.h>
%%#include <stdlib.h>
%%#include <stdio.h>
  %%char rob[10] ;
  char *roba;
  assign roba to "rawdata" ;
  monitor roba ;
  float ch1 ;
  float ch2 ;
  float ch3 ;
  float ch4 ;
  float ch5 ;
  assign ch1 to "PV1";
  assign ch2 to "PV2";
  assign ch3 to "PV3";
  assign ch4 to "PV4";
  assign ch5 to "PV5";
  int v ;
  float z ;
  %%extern char *wa1 ;
  %%char *sign="+-" ;
%{
  rob=&roba
  v=rob[0];                 /*Get first char from string*/
  wa1=strpbrk(rob, "+-");   /*Break string at +-,rest is wa1*/
  z=(float)wa1;             /*convert string to float z*/
 }%
ss ss1 {
  state state1 {
     when (    v==1) {
         ch1 = z; pvPut(ch1);
     } state state2
  }
  state state2 {
     when (    v==2) {
         ch2 = z; pvPut(ch2);
     } state state3
  }
  state state3 {
     when (    v==3) {
         ch3 = z; pvPut(ch3);
     } state state4
  }
  state state4 {
     when (    v==4) {
         ch4 = z; pvPut(ch4);
     } state state5
  }
  state state5 {
     when (    v==5) {
         ch5 = z; pvPut(ch5);
     } state state1
  }
}

What are we doing wrong??  The C code embedded in the sequencer code
above compiles without any issues under gcc.  Being new to
sequencer/state notation language, we are lost here...

--
Dr. Dirk Zimoch
Swiss Light Source
Paul Scherrer Institut
Computing and Controls
phone +41 56 310 5182
fax   +41 56 310 4413

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System