nettogrisen
Lifetime Supporting Member
I'm going to start a new project soon where (i think) I'm going to be using a 1769-L32E with 100+ slaves on modbus RTU.
I've succesfully used the L32E with a 1769-SM2 card for modbus communications in the past.
My concern this time is the number of nodes.
I was thinking that I would use a few MSG instructions in a loop and load different node addresses into the MSG instructions on every pass. The thing is that I have to move an "address" or a "tag" into the msg_instruction.SourceLink and not a value, as the SM2-module works by passing the MSG instruction a structure containing slave address, modbus address ect., and it also takes a structure to store response data in. So what i basically need is a *pointer like in C.
Does anybody have any experience with this?
I suspect that I might be better of looking at Siemens?
I've succesfully used the L32E with a 1769-SM2 card for modbus communications in the past.
My concern this time is the number of nodes.
I was thinking that I would use a few MSG instructions in a loop and load different node addresses into the MSG instructions on every pass. The thing is that I have to move an "address" or a "tag" into the msg_instruction.SourceLink and not a value, as the SM2-module works by passing the MSG instruction a structure containing slave address, modbus address ect., and it also takes a structure to store response data in. So what i basically need is a *pointer like in C.
Does anybody have any experience with this?
I suspect that I might be better of looking at Siemens?