Posted ByLeon on September 12, 2001 at 13:55:28:
In Reply to: Modbus posted byLuc Bastien on September 12, 2001 at 13:51:53:
I have not used Wonderware before, but some customers has used Interllusion with the T100MD1616+ and I have used National Instrument Lookout with it before so I think they should be quite similar. I will share with you what I know about in Lookout and hope it is of some helps.
When you construct an object in Lookout, you can specify the element as a MODICON Holding Register. Then you will be prompted to select the holding register address. Since T100MD maps it I/Os as follow:
inputs #1-#16 40001.1 - 40001.16,
inputs #17-#32 40002.1 to 40002.16 etc
(as shwon in Table 5.1 in the User's manual). You just have to enter it accordingly.
MODBUS protocol actually defines the I/O addresses as zero-offset (meaning starting from zeros) while its HOLDING REGISTER address is 400001-offset (e.g. starting from 40001). So if you are handling the binary address stated in the protocol, then the holding register #40001 has a binaryaddress 0000, #40002 has a binary address 0001,etc. I am not sure whether if that is what is required by Wonderware. If so, then input #1 to #16 will maps tobinary address 0000 (16 bit hex word), output #1 to #16 willmap to binary address 0010 hex. etc.
Hope this helps.