Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Tue, 5 Jun 2018 11:28:44 +0200

For fixed-length input you can use maxInput=number_of_byes; instead of a
terminator.

   I tried bracketing my read of 'ACK' with 'MaxInput=1' and 'MaxInput=0',
but it didn't help - still nothing in my PV.

At them moment, you cannot change variables at run-time. The protocol

starts and runs with the last setting. Thus this:

MaxInput=1;
in ACK;
MaxInput=0;
in "...";

Actually executes:
MaxInput=0;
in ACK;
in "...";

This is because setting variable like MaxInput is evaluated when the

protocol is loaded, not at run-time like the 'in' command. I plan to

change that in the future.

Wahat I meant was:
read_version {
      MaxInput=...;
      out STX, "001?f" ETX, "%<xor8ff>";
      in ACK, STX, "001 f%[^\003]", ETX, "%1<xor8ff>";
   }

Read everything including ACK as one fixed length line.

In cases you have no terminator string but constant length input, using

MaxInput saves you from using readTimeout as the line terminator. Thus

you have no delay at the end of the input and no danger that two lines

join to one in case readTimeout is too long.

Dirk

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System