AC800M, PM860, MODBUS RTU
Hello, thanks for your reply to my original quesiton.
I have tried to setup a simple read block to see if i can establish a connection with no success. Unfortunatly my expirience with Controll builder and AC800M is fairly limited so any help i can get to complete this project is appreciated.
The slave device im using is the ABB CB PR123, the data sheet for the modbus memory map for the device is found in this pdf http://www05.abb.com/global/scot/scot209.nsf/veritydisplay/9154a4bc3e1da39ac125
The PM860 modbus port is com3, the com3 port is using RS232 standard for sending, and the PR123 is using RS485, i am using a simple converter between the devices, this should cause any problems?
I have added some image files on how i have constructed my program and what variables i am using, if i have understood it correct in the read adress input should be qw247#700, if i want to read function 700 on slave device ID247, but i have no success.
First prio is to establish a connection to see if communication is even possible, and then start to read and write.
You need to toggle MBRead_1.Req each time you want to read a block of data. You cannot connect it to "Enable_Com"
1. Connect "Error" of MBConnect_1 to a variable called "ERR"
2. Insert an AND after MBConnect_1
3. Insert a PulseGen after AND
4. Pulsegen Enable = STA and NOT ERR
5. Connect output of PulseGen to MBRead.Req
6. Set suitable period & pulse times for the pulse gen to read data at the required rate.
The Pulsegen will generate read requests whenever the connection is valid and there is no error on the MBConnect block.
To check error status codes on the MBConnect and MBRead blocks just search for the error code ( in your case "-5324" ) in the on line help. This trick works for any status code on any block.
you can read more about modbus configuration in http://www402.abbext.com/MODBUS-Configuration-CI853-For-Beginners_1-0_a915.aspx and in Control Builder M help, type "mbread" in Search
about StartAddr read 3BSE035980-511_en_System_800xA_Control_5.1_AC_800M_Config.pdf
Source: MODBUS Configuration CI853 - For Beginners (1.0)