RE: Newbie question about SNL

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

Hi Dariush,

 

I don’t understand this block:

 

                when (test==3) {
                        command=4;
                        pvPut(command, SYNC);
                        pvPut(motor, 1, SYNC); 
                        test=6;
                        pvPut(command, SYNC);
                        pos=pvGet(motor, SYNC);
                        printf("IOC and Device %s\n", motor);
                        printf("Position =%f\n", pos);
                        test=0;
                        pvPut(test);
                } state idle

 

Why are you setting “test=6”, since you never use “test” before you set it to 0 later in the block.  Is that an error and you meant to set “command=6”?

 

In the code you included you never define the “state loop” state.  What is that?

 

I think you should consider using the EPICS sscan record for this task rather than an SNL program.

Mark

 

 

From: Dariush Hampai <dariush.hampai@lnf.infn.it>
Sent: Friday, November 28, 2025 10:35 AM
To: tech-talk@aps.anl.gov; Mark Rivers <rivers@cars.uchicago.edu>
Subject: Newbie question about SNL

 

Hi community,
i'm trying to create a sequencer by SNL.
I would like to create a scan with a motor and for each step an acquisition.
Using the db of the scan IOC, I defined my IOC to control

 "{user}:motor" and "{user}:create_command_label" are in the scan IOC db, and I need them to generate the record that I want to control

[…]
string motor;
assign motor to "{user}:motor";
monitor motor;
double command;
assign command to "{user}:create_command_label";
monitor command;
[…]

ss scan_test {
        state init {
                when (test==0) {
                        printf("Ready for Loop\n");
                        } state idle
        }
        state idle {
                when (test==1) {
                        printf("Start Loop\n");
                        test=2;
                        pvPut(test);
                } state loop
                when (test==3) {
                        command=4;
                        pvPut(command, SYNC);
                        pvPut(motor, 1, SYNC); 
                        test=6;
                        pvPut(command, SYNC);
                        pos=pvGet(motor, SYNC);
                        printf("IOC and Device %s\n", motor);
                        printf("Position =%f\n", pos);
                        test=0;
                        pvPut(test);
                } state idle
       }
[...]
}

When I start the IOCs (by procServ), and I pass in the test=3 state I receive:
IOC and Device mm4006_1_1_2:pos
Position =0.000000

However
caget mm4006_1_1_2:pos
mm4006_1_1_2:pos               1000

Where do I wrong?

 

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