Text Field - Text value clears after loosing focus

Ignition
1

The ignition String tag binds perfectly fine to S71200 PLC tag while displaying the correct value. As soon as I change the text field value in ignition and click outside the text field, the value is cleared along with writing and empty string to the PLC tag.

Correcting the String value in the PLC shows up again in ignition, but continues to clear when writing back to the PLC.

2

Which driver are you using?

3

Hi David,

I'm using the Siemens S7-1200 Driver

4

Can you share the DB you are writing to, and the setup of the tag address?

5

The Velocity String is cleared after focus has been removed.

Ignition Designer
Ignition Designer1379×1160 98.6 KB

DB49
DB491427×599 79.6 KB

Database is SQL Server

SQL DB
SQL DB3401×790 83.1 KB

6

If you look in the link, the correct address is STRING.LEN
A string in siemens is always starting at the start of a whole byte/word, so there is no need for a bit marker. Instead, you omit the.0 shown in the offset column in the DB. The number after the . is the length in characters. The string you show is 256 length, which is longer than the 210 characters able to be accessed by the siemens driver.

You can try:
[Applicator - Safety]DB49.STRING256
[Applicator - Safety]DB49.STRING256.200

7

Lengend! The dot notation for STRING LEN was where I went wrong.

Thanks heaps.

8

[Applicator - Safety]DB49.STRING256.200

STRING256 is the DB starting byte address.

STRING256.200 is the number chars writing to the PLC, therefore STRING256.0 was writing 0 chars to the PLC, hence the blank values.