EPICS Home

Experimental Physics and Industrial Control System


 
1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  <20122013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024  Index 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  <20122013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
<== Date ==> <== Thread ==>

Subject: RE: stream device string/hex parsing
From: <[email protected]>
To: <[email protected]>
Date: Mon, 9 Jul 2012 17:19:25 +0000
Have you set
extrainput = Ignore; 
In your protocol file?

Even so a better strategy would be to use redirection:

record (ai, "G2:ADC16-TEST_CH0")
{
    field (DESC, "ADC0")
    field (DTYP, "stream")
    field (INP, "@adc16.proto getADCs(G2:ADC16-TEST) ADC16_1")
    field (SCAN, "5 Second")
    field (FLNK, "G2:ADC16-TEST_CH1")
}
record (ai, "G2:ADC16-TEST_CH1")
{
    field (DESC, "ADC1")
    field (FLNK, "G2:ADC16-TEST_CH2")
}

---

getADCs {
    out ":0400000008..%<checksum>";
    in ":0410%4x%(\$1_CH1.VAL)4x%(\$1_CH2.VAL)4x%(\$1_CH3.VAL)4x%(\$1_CH4.VAL)4x%(\$1_CH5.VAL)4x%(\$1_CH6.VAL)4x%(\$1_CH7.VAL)%<checksum>";
}

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Gerrit Kühn
Sent: 09 July 2012 16:50
To: [email protected]
Subject: stream device string/hex parsing

Hi all,

I have set up stream device to talk to an ADC converter via rs232. The
records and protocols look like this:

---
record (stringin, "G2:ADC16-TEST")
{
    field (DESC, "answer string")
    field (DTYP, "stream")
    field (INP,  "@adc16.proto getData ADC16_1")
    field (SCAN, "5 second")
}

record (ai, "G2:ADC16-TEST_CH0")
{
    field (DESC, "ADC0")
    field (DTYP, "stream")
    field (INP, "@adc16.proto getADC0 ADC16_1")
    field (SCAN, "I/O Intr")
}
[...] 8 adc channels
---

---
Terminator = CR LF;

getData {
    out ":0400000008..";
    in "%41c";
}

getADC0 {
    in "%*5c%4x";
}
[...] 8 adc channels
---


I get the full answer string from the device into the first record. It looks like this:

---
pt@pt-steward ~ $ caget G2:ADC16-TEST
G2:ADC16-TEST                  :041000000000000000000000000000000000EC
---


The string needs to be parsed into numerals. The first 5 characters (command string) are not needed, neither the last two (checksum).
The remaining characters need to be processed in groups of 4 (16 bit per channel) and parsed from hex. This is what I intend to do with 
in "%*5c%4x";
for the first channel. The next channel would skip 9 characters, the next 13 and so on.
However, this does not appear to work out. Everything works fine when I change the records to "stringin" type and parse for "%*5c%4c" instead. But parsing hex into ai never yields a single value.

Any ideas why this does not work, and how I can be made work?


cu
  Gerrit
-- 
Scanned by iCritical.


Replies:
Re: stream device string/hex parsing Gerrit Kühn
References:
stream device string/hex parsing Gerrit Kühn

Navigate by Date:
Prev: EPICS channel access performance test tanushyam bhattacharjee
Next: New version of LabVIEW-EPICS-interface CA Lab Carsten Winkler
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  <20122013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024 
Navigate by Thread:
Prev: stream device string/hex parsing Gerrit Kühn
Next: Re: stream device string/hex parsing Gerrit Kühn
Index: 1994  1995  1996  1997  1998  1999  2000  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  <20122013  2014  2015  2016  2017  2018  2019  2020  2021  2022  2023  2024