Experimental Physics and
Industrial Control System

Eric Norum <[email protected]> · Fri, 4 May 2012 10:14:13 -0700

I thought that I'd give this a try here so I dug up an old Tektronix TDS 210 oscilloscope with a serial port and connected it to my OS X machine through a LAN/Serial adapter.

Here are the salient portions of my st.cmd file:
drvAsynIPPortConfigure("L0","xxxxxx.lbl.gov:4095 COM",0,0,0)
asynSetOption("L0", 0, "baud", "9600")        <<<<===== Scope has a 19200 setting, but can't seem to accept commands at that rate.  Perhaps if I had a cable that did the right things with the handshaking lines I could set crtscts=Y and run at 19200
asynSetOption("L0", 0, "bits", "8")
asynSetOption("L0", 0, "parity", "none")
asynSetOption("L0", 0, "stop", "1")
asynSetOption("L0", 0, "clocal", "Y")
asynSetOption("L0", 0, "crtscts", "N")
….
dbpf hctest:HCparms.PROC 1
epicsThreadSleep(1)
dbpr hctest:HCparms
dbpf hctest:HC.PROC 1
epicsThreadSleep(60)
dbpr hctest:HC 1

The StreamDevice prototype file:
getHC {
    InTerminator = "";
    ReplyTimeout = 5000;
    ReadTimeout = 2000;
    out "HARDC STAR";
    in "%0r";
}
getHCparms {
    out "HARDC?";
    in "%\$1[^\r\n]";
    ExtraInput = Ignore;
}

The EPICS database:
record(stringin, "$(P)$(R)HCparms")
{
    field(DESC, "Hardcopy parameters")
    field(DTYP, "stream")
    field(INP,  "@devhctest.proto getHCparms(39) $(PORT) $(A)")
}
record(waveform, "$(P)$(R)HC")
{
    field(DESC, "Hardcopy")
    field(DTYP, "stream")
    field(INP,  "@devhctest.proto getHC(99999) $(PORT) $(A)")
    field(FTVL, "CHAR")
    field(NELM, "100000")
}

=================================================

I''ve found this to be quite solid in reading out the screen dump.   Here's a typical IOC session:
dbpf hctest:HCparms.PROC 1
DBR_UCHAR:          1         0x1                 
epicsThreadSleep(1)
dbpr hctest:HCparms
ASG:                DESC: Hardcopy parameters               DISA: 0             
DISP: 0             DISV: 1             NAME: hctest:HCparms                    
SEVR: NO_ALARM      STAT: NO_ALARM      SVAL:               TPRO: 0             
VAL: BMP;RS232;LANDSCAPE                
dbpf hctest:HC.PROC 1
DBR_UCHAR:          1         0x1                 
epicsThreadSleep(60)
dbpr hctest:HC
ASG:                BUSY: 0             DESC: Hardcopy      DISA: 0             
DISP: 0             DISV: 1             NAME: hctest:HC     NORD: 38462         
SEVR: NO_ALARM      STAT: NO_ALARM      TPRO: 0             VAL: 0x0  

=================================================

However…
  - just reading out the waveform values would be significantly quicker.
  - 9600 baud RS-232 seems like a pretty horrible way to communicate with an oscilloscope.  

-- 
Eric Norum
[email protected]

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System