Schneider Electric S7 Supported Device Addresses, Unintended Equipment Operation, Fetch/Write

SIMATIC S7 Ethernet

Supported Device Addresses

Overview

WARNING

UNINTENDED EQUIPMENT OPERATION

Design your system to avoid conflicting write processes between the target machine and PLC program. Values on the PLC and target machine will be incorrect if:

zThe target machine and PLC program attempt to simultaneously write to the same register.

zPLC programs or other devices write 16-bit word values to registers being accessed in a bitwise manner.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

The following tables list the device address ranges you can enter from the Device Address keypad.

For actual device address ranges supported by the PLC, refer to the corresponding PLC manual.

Fetch/Write

		Device	Bit Address*1	Word Address	16 bit	32 bit
	Input*2		I00000.0-I65535.7	IW00000-IW65534*7
	Output* 2		Q00000.0-Q65535.7	QW00000-QW65534*7
	Marker*2		M00000.0-M65535.7	MW00000-MW65534*7	H/L*8	H/L*8
	Data Block*2*6		DB00001.DBX00000.0 -	DB00001.DBW00000 -
			DB00255.DBX16383.7	DB00255.DBW16382*7
	Timer Word*3*4*5		—	T00000-T65535
	Counter Word*3*4*5		—	C00000-C65535
*1		Read-modify-write. When you write to one of these bit addresses, the target
		machine reads the entire word address, sets the defined bit, then returns the new
		value to the PLC. If the ladder program writes data to this word address during
		the bit read/write process, the resulting data may be incorrect.
*2		Device size is 1 byte.
*3		Device size is 2 bytes, or 1 word.
*4		Valid range in BCD is 0000 to 0999.
*5		Read-only.

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