This module establishes a redundant connection via the standard network interface of the computer or an additional network card.

Note
	The module S7-Xplorer redundant seizes two licensed connections. Please check whether the total number of licensed connections is also sufficient when using redundant modules.

ibaPDA always reads data only from one CPU, which is called active CPU. It is decided on the basis of the CPU status and the connection status from which CPU the data are taken.

With only one CPU connected, data is taken from this CPU. If both CPUs are connected and only one of them in the RUN status, ibaPDA chooses the latter CPU is chosen. If both are connected and in RUN status, then ibaPDA chooses the first CPU (connection 0). This does not apply to a S7-400H system. In that case ibaPDA chooses the CPU with the RUN MASTER status.

If there is a change of the CPU status or the connection status of the active connection, ibaPDA switches the connection. A change of the CPU status or the connection status of the currently inactive connection, does not cause a switch-over of the connection.

This is the coupling of two "normal" S7-Xplorer connections that ibaPDA switches in case of an error. It is not a so-called "fault tolerant connection". This is why there may be signal gaps of 1 to 2 seconds during a switching operation.

The connected controllers may be an S7-400H controller pair (fault tolerant) or two standard S7 controllers. A prerequisite is that the acquired operands occupy in both controllers identical addresses.

ibaPDA supports the following controllers, connection modes and selection methods:

Controller	Connection mode and signal selection
	TCP/IP			PC/CP			TCP/IP S7-1x00
	ABS	SYM	CFC	ABS	SYM	CFC	ABS	SYM	CFC
S7-300	X	X	X	X	X	X	-	-	-
S7-400	X	X	X	X	X	X	-	-	-
S7-400H	X	X	X	X	X	X	-	-	-
S7-1200	X	-	-	-	-	-	-	-	-
S7-1500	X	-	-	-	-	-	-	-	-

Explanation: ABSolute address, SYMbolic, CFC connector

Note

S7-1500R/H controllers do not require a redundancy module. In addition to the device IP address, these controllers use a system IP address for communication with other devices. The system IP always points to the primary CPU, ensuring that communication is automatically redirected to the new primary CPU in the event of a failure. Therefore, specify the system IP address in the S7-Xplorer module. For more information, see https://support.industry.siemens.com/cs/de/en/view/59192925/166918714891.

Note
	A download of the HW Config is not possible while ibaPDA acquires data. Stop the ibaPDA data acquisition first.

ibaPDA supports the following operand types:

Selection via	Analog	Digital
S7-300 S7-400	EB, AB, MB, PEB, DBB EW, AW, MW, PEW, DBW ED, AD, MD, PED, DBD T, Z	E, A, M, DBX
S7-1200 S7-1500	EB, AB, MB, DBB EW, AW, MW, DBW ED, AD, MD, DBD	E, A, M, DBX

For more information on the module settings see General module settings.

Connection configuration

Configure both connections on the tabs Connection 0 and Connection 1. You can change the name of the tabs in the Connection name fields.

For details concerning the module settings see Module S7-Xplorer.

The option Enable Software Redundancy refers to a Siemens software package that enables redundancy for standard automation systems of the S7-300 and S7-400. The status bit DB 101.DBX 9.0 indicates the state "Station is Master."

For diagnosis of the status of both connections, there are special signals available on the Digital tab. These occupy the first 4 signal positions:

Table Status signals of the redundant connection

Signal	Meaning
$PDA_PrimaryConnected	Connection 0 established
$PDA_PrimaryActive	Data acquisition active over connection 0
$PDA_SecondaryConnected	Connection 1 established
$PDA_SecondaryActive	Data acquisition active over connection 1

One signal out of the two signals {PDA_PrimaryActive} and {PDA_SecondaryActive} is always TRUE even if none of the two connections is active.