RE: Reading multiple parameters from an incoming message.

[Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Hi Ji Li,

 

Sorry for the delay in replying.  Maybe you have figured this out?

 

If not, I have some questions:

 

Your .db file passes 3 arguments to the protocol file, %(P), $(Q), $(CMD).  But in the protocol file I only see \$1 and \$2, not \$3.  Is this correct?

 

You have commented out the line that defines the input terminator in the protocol file:

#InTerminator = 0x11;

 

How will asyn know when to return a string without a timeout if there is no terminator defined?

 

I think the protocol would be easier to read if you change this:

in "%d %*d %*d %*c%*c%*c%*c%*c%*c\n%*d %*d %*d %*c%*c%*c%*c%*c%*c\n" $ax_status;

 

to this:

in "%d %*d %*d %*6c\n%*d %*d %*d %*6c\n" $ax_status;

 

Mark

 

 

From: Li, Ji <liji at bnl.gov>
Sent: Thursday, December 24, 2020 5:36 PM
To: Mark Rivers <rivers at cars.uchicago.edu>
Cc: tech-talk at aps.anl.gov
Subject: 回复: Reading multiple parameters from an incoming message.

 

Hi Mark,

 

I was referring to the PV for RATEA - $(P){$(Q)-Ax:A}:RATE:RBV.

 

Please see the attached files for the protocol, the database, the substitutions file, and the st.cmd. I only worked on Independent Condition to operate the two syringes separately. For better clarity I removed other protocols/databases definitions.

 

The .proto file contains the definition of this protocol and the referenced macro.

 

I have several .db files for different categories of information (rate/volume/time/...). The attached .db file defines the status PV - currently only RATEA. I expect implementation of other PVs that get values from this status message would be similar once I'm done with RATEA.

 

 

Best,

 

-Ji Li

 

 

---

发件人: Mark Rivers <rivers at cars.uchicago.edu>
发送时间: 2020年12月24日 14:53
收件人: Li, Ji <liji at bnl.gov>
抄送: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
主题: Re: Reading multiple parameters from an incoming message.

 

Hi Ji Li,


Can you send the rest of the database and protocol files, or at least the Status record and the $ax_status definition.

> The PV was showing INVALID(UDF_ALARM). Since the IOC didn't throw errors, I suppose the message was parsed correctly. How could this alarm have been caused?

Which PV are you referring to?

Mark



________________________________
From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Li, Ji via Tech-talk <tech-talk at aps.anl.gov>
Sent: Thursday, December 24, 2020 11:04 AM
To: tech-talk at aps.anl.gov
Subject: Reading multiple parameters from an incoming message.

Hi,

I'm working on an EPICS package for a Harvard Pump 33 DDS syringe pump using streamdevice protocols. I need to read several parameters from an incoming message that combines the status of two axes/syringes, which has the following format:

RATEA TIMEA VOLA STATUSA
RATEB TIMEB VOLB STATUSB

RATEA/B, TIMEA/B and VOLA/B are integers, and STATUSA/B are 6-character strings with each character indicating a specific status.

I'm trying to parse the message using multiple protocols and records. For RATEA, only grab the first integer:

Protocol:
=======================
getStatusRateAxA {
    out "status";
    in "%d %*d %*d %*c%*c%*c%*c%*c%*c\n%*d %*d %*d %*c%*c%*c%*c%*c%*c\n" $ax_status;
}
=======================

Record:
=======================
record(ai, "$(P){$(Q)-Ax:A}:RATE:RBV") {
  field(DESC, "Axis A rate readback")
  field(DTYP, "stream")
  field(INP, "@pump33dds.proto getStatusRateAxA($(P), $(Q), $(CMD)) $(PORT)")
  field(PREC, "0")
}
=======================

The .substitutions file referring to this record was loaded without errors. When I tried to retrieve status information, the IOC shell printed the following information without errors:

=======================
epics> 2020/12/24 11:29:06.797 /dev/ttyUSB0 write 8
status\r\n
2020/12/24 11:29:06.833 /dev/ttyUSB0 read 71
50000000000 0 22307784 w...I.\n83333333330 24723 2055394602192 i...I.\n::
=======================

"::" in the incoming message should be parsed by "$ax_status" in the protocol and it worked for other messages.

The PV was showing INVALID(UDF_ALARM). Since the IOC didn't throw errors, I suppose the message was parsed correctly. How could this alarm have been caused?

Best,

-Ji Li