Features
Original instructions
About us
Overview
Each Quantum CPU includes both a Modbus and Modbus Plus communications port. The features offered by both these communication protocols are listed in the following table.
Modbus and Modbus Plus Features Table
The following table shows the Modbus and Modbus Plus features.
Features
Modbus
Modbus Plus
Technique
Slaves polled by a master
Peer-to-peer, token rotation
Speed
19.2 kbaud typical
1 Mbaud
Electrical
RS-232, various others
RS-485
Distance without repeater
RS-232, 50 ft. (15 m)
1,500 ft. (457 m)
Media
Various
Twisted pair, Fiber optics
Max nodes per network
247
64
Max network traffic
300 registers/sec @ 9.6 kbaud
20,000 registers/sec
Programming
Yes
Yes
Read/Write data
Yes
Yes
Global data
No
Yes
Peer Cop
No
Yes