Experimental Physics and
Industrial Control System

All,

 

I would like to get an opinion from you all about whether these “architectures” are appropriate for StreamDevice. I’ve been looking at some posts on Tech-Talk about the general use for StreamDevice, specifically when there are multiple commands. Suppose I need to implement EPICS drivers for an instrument that has two commands: cmd1, cmd2, and cmd3. Here are some “architectures” I’ve tried and used:

 

1. “Processing chain” method

 

record(ao, “cmd_1_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd1 $(PORT)”)

              field(FLNK, “cmd_1_get”)

}

 

record(ao, “cmd_2_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd2 $(PORT)”)

              field(FLNK, “cmd_2_get”)

}

 

record(ao, “cmd_3_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd3 $(PORT)”)

              field(FLNK, “cmd_3_get”)

}

 

record(ai, “cmd_1_get”)

{

              field(SCAN, “1 second”)

              field(INP, “@instrument.proto getCmd1 $(PORT)”)

              field(FLNK, “cmd_2_get”)

}

 

record(ai, “cmd_2_get”)

{

              field(SCAN, “Passive”)

              field(INP, “@instrument.proto getCmd2 $(PORT)”)

              field(FLNK, “cmd_3_get”)

}

 

record(ai, “cmd_3_get”)

{

              field(SCAN, “Passive”)

              field(INP, “@instrument.proto getCmd3 $(PORT)”)

}

 

 

 

2. Fanout method

 

record(fanout, “slow_scan”)

{

              field(SCAN, “1 second”)

              field(LNK0, “cmd_1_get”)

              field(LNK1, “cmd_2_get”)

              field(LNK2, “cmd_3_get”)

}

 

record(ao, “cmd_1_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd1 $(PORT)”)

              field(FLNK, “cmd_1_get”)

}

 

record(ao, “cmd_2_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd2 $(PORT)”)

              field(FLNK, “cmd_2_get”)

}

 

record(ao, “cmd_3_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd3 $(PORT)”)

              field(FLNK, “cmd_3_get”)

}

 

record(ai, “cmd_1_get”)

{

              field(SCAN, “Passive”)

              field(INP, “@instrument.proto getCmd1 $(PORT)”)

}

 

record(ai, “cmd_2_get”)

{

              field(SCAN, “Passive”)

              field(INP, “@instrument.proto getCmd2 $(PORT)”)

}

 

record(ai, “cmd_3_get”)

{

              field(SCAN, “Passive”)

              field(INP, “@instrument.proto getCmd3 $(PORT)”)

}

 

 

 

3. Record scan method

 

record(ao, “cmd_1_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd1 $(PORT)”)

}

 

record(ao, “cmd_2_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd2 $(PORT)”)

}

 

record(ao, “cmd_3_set”)

{

              field(SCAN, “Passive”)

              field(DTYP, “stream”)

              field(OUT, “@instrument.proto setCmd3 $(PORT)”)

}

 

record(ai, “cmd_1_get”)

{

              field(SCAN, “1 second”)

              field(INP, “@instrument.proto getCmd1 $(PORT)”)

}

 

record(ai, “cmd_2_get”)

{

              field(SCAN, “1 second”)

              field(INP, “@instrument.proto getCmd2 $(PORT)”)

}

 

record(ai, “cmd_3_get”)

{

              field(SCAN, “1 second”)

              field(INP, “@instrument.proto getCmd3 $(PORT)”)

}

 

 

Are all valid or is there one that is better than the other. Or is there an even better one that I haven’t thought of…

 

Thanks,

Andy