Modbus read builder...?

[ORSO2001]

Dear All,

 

 searched in the forum but I don't found what I need...and I can't insert a pic of the "question"..I can upload only 29.9 Kb!

 

I tried to use the element "modbus read builder" to read a lot of registers together...

 

in the point "A" I insert an "modbus request" with: protocol=0; function n°=3; slave ID=1; start address=0; number of operands=39; ethernet trns.= nothing.

 

in the point "B" I insert a BUFFER (that I created in GLOBAL tag) with 8 "array".

 

In the point "D" I insert a "modbus request descriptor" with: expected response=43 (I have read it after the first test...and is what I expected...if I have understood the modbus RTU protocol); protocol=0;function=3; start address=20; number of operands=19; ethernet=nothing.

 

For the point "C" (request size) I tried different "tag" (buffer, int,uint..) but nothing seems work!

 

When I tested the "program" I have had the following response from the buffer in the point "B": 1,3,0,0,0,39,5,208.

in the tags that I tried to use for the answer (it is an answer?) I have always "0" in each point...

 

What I have to do?

thanks in advance

 

[ORSO2001]

Dear All,

 

yesterday I have downloaded the last sample programs from the site and I understand that I really wrong everything...please accept my apologise if I have wasted your time with my uncorrect question...I am less then a beginner and I have learn more...now I know that I have to insert a tag with indicate the array lenght in the slave session and what I have tried before is for the TCP.

I hope next time my question will be done in a properly way.

Thanks