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Get a float or integer with MODBUS?
/ Most recent by james77
james77 Posts: 10 Apprentice
matthewd92 Founding Pro, Tactile Sensor Beta Testers Posts: 1,267 HandyWith EthernetIP/Profinet you would store the value directly in the register with the PLC then the robot would use one of the read methods such as read_float_register(n) (name may be slightly different) to read the value.With modbus you would have to convert the number to an integer and then convert it back on the robot. Easy enough to do. Modbus is just limited on what can be transmitted. It’s an integer based system. It’s a fairly old protocol and also slow. If you need the value for real time control the other fieldbus protocols are much faster, think 5X or 10X faster. We’ve recorded round trip write to read, so robot writes to a register, PLC reads it and writes to a register which the robot receives and reads in the 40ms range. Modbus was around 300-400 ms.
Besides Ethernet IP/Profinet (let's consider MODBUS is only option), is it impossible to do the same with the MODBUS?