GE P485 instruction manual Memory Map, Address Contents Access

DATA EXCHANGE

	PLC memory
	I/O inputs	I/O outputs
	Current Ia	CT PRIMARY
The PLC exchanges data			The PLC exchanges data
via the Profibus network			via the Profibus network
between its internal input			between its internal output
area and the input area			area and the output area
of the P485	Profibus network		of the P485
	Internal memory buffer
	of the P485
	Input data area	Output data area	General data area
0x0000	0x0200	0x0400
	Current Ia	CT PRIMARY

The data in the input area of the P485 contains data received from nodes on the Modbus sub-network (sent in to the P485 from the sub-network)

The data in the output area of the P485 contains data received from Profibus. In this case, it is the CT PRIMARY setting of the PQMII meter.

Modbus sub-network

Modbus slave (e.g. PQMII)

CT PRIMARY setting

Current Ia actual value

Figure 3-2: Data exchange overview

Memory Map

MEMORY LOCATIONS When configuring the sub-network, use the memory locations shown below:

Address	Contents	Access
0x0000 to 0x0001	Status register	read/write
0x0002 to 0x00F3	Input data area	read/write
0x00F4 to 0x01FF	Reserved	-
0x0200 to 0x0201	Control register	read only
0x0202 to 0x02F3	Output data area	read only
0x02F4 to 0x03FF	Reserved	-
0x0400 to 0x7FF	General data area	read/write

3–2 P485 MODBUS TO PROFIBUS CONVERTER – USER GUIDE