Emerson Liebert HiPulse E Series - 5. TECHNICAL DESCRIPTION OF THE PROTOCOL; 5.1 General features of the MODBUS;JBUS RTU protocol

Communication System Manual UPS System: HIPULSE E
(Modbus/Jbus Interface) Description of Protocol
(04/07) Page 5-1
5. TECHNICAL DESCRIPTION OF THE PROTOCOL
This section provides a detailed description of how the standard MODBUS RTU protocol is implemented in the UPS
P/N 4550005F Operator Logic board (or MSS Operator Logic P/N 4550008I).
For further information not supplied herein, please refer to the document outlining the standard MODBUS RTU
protocol issued by MODICON and available from its Internet site at http://www.modicon.com/techpubs
5.1 General features of the MODBUS/JBUS RTU protocol
The Modbus/Jbus RTU protocol is handled using the serial line managed directly by the Siemens 80C166M
microcontroller, which uses the RS485 interface.
This serial line may be used to set up a network of connected UPSs by connecting Operator Logic boards to one another
(see Fig. 3-6).
This function and all other settings already made to set up a network will of course be lost when the MODBUS/JBUS
RTU protocol is selected.
This protocol may be used to connect the Operator Logic board to either a MODBUS MASTER or a JBUS RTU
MASTER. This is because the JBUS RTU protocol is a subset of the MODBUS RTU protocol, and functions common
to both protocols have been used to implement the desired requests.