Siemens SIMATIC S7-400 manual Technical data Point-to-point connection Application

© Siemens AG 2011

Point-to-point connection

Point-to-point link via communications processors (CPs) is an extremely powerful and low-cost alternative to bus systems. The advantage of point-to-point links over bus systems is es- pecially pronounced when only a few (RS 485) devices are to be connected to the SIMATIC S7.

The CPs can also easily link third-party systems to the SIMATIC S7. Thanks to the great flexibility of the CPs, different physical transmission media, transmission rates or even cus- tomized transmission protocols can be implemented.

The CPs have a rugged plastic housing with LEDs for displaying operating states and faults.

For each CP there is a configuring package on CD with elec- tronic manual, parameterization screen forms and standard function blocks for communication between the CPU and the CP.

The configuration data are stored in a system block and backed up in the CPU. When modules are replaced, the new module is therefore immediately ready for use.

With the S7-400 point-to-point link modules, adaptation to the physical transmission media is achieved by plugging in the relevant interface submodules, without the need for external converters.

SIMATIC S7

PC	Printer	Robot	BDE
		control	terminal

Point-to-point links for SIMATIC S7-400

Scanner Barcode reader

Process controller

SIMOVERT

SIMOREG

Modem

PLC	_XX_00687
	_ST70G
3rd party

Technical data: Point-to-point connection

Application	High-speed response	Interconnection
	with low data volumes	Low-cost:	High-speed:
		With one variable	With two variable inter-
		interface	faces
Transmission rate	High (115 200 bit/s)	Low (38 400 bit/s)	High (115 200 bit/s)
Loadable protocols			MODBUS Master (-1AA.),
(Order No. group: 6ES7 340-)			MODBUS Slave (-1AB.),
			Data Highway (-1AE.)
Module	CP 440	CP 441-1	CP 441-2
Order No. group: 6ES7	440-1.	441-1.	441-2.
Physical transmission media

RS 232C (V.24)
20 mA (TTY)
RS 422/485 (X.27)	● (up to 32 nodes)

All transmission methods, all interface modules, plug-in, serial

Integrated transmission protocols

ASCII

Printer driver

3964 (R)

RK 512

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SIMATIC Modular Controllers 59