Siemens EN 50295 manual Module F90, Eeee

AS-Interface Slaves

I/O modules for operation in IP20 control cabinet

Module F90

■Function

Principle of operation of the 16E module (3RG9 002-0DE00 and 3RG9 004-0DE00)

The 16 inputs are arranged in four groups of four inputs.

Only one group is permitted to be activated at a time. The PLC activates each group in sequence and reads the four input sig- nals into the process image of the inputs in each case. The user program assigns the input information to the appropriate groups, i .e. the output process image of the PLC must corre- spond to the set output of the module otherwise input information will be read in from the wrong group.

When a fault occurs in AS-i transmission, it can take up to three AS-i cycles (15 ms) until the output image of the slave corre- sponds to the output image of the master and therefore of the PLC. It can also take three cycles to transfer the input image of the slave. If messages to a particular slave are faulty over more than three consecutive AS-i cycles, the slave outputs a "Config error" to the master. The input image in the master is set to zeroes and the fault bit is set in the PLC.

Example: Response of the output image and the input image in the master and in the slave to faulty AS-Interface transfer

AS-	PLC	Master	Module		Note	00321
Inter-
face-						NSA0
cycle	PIQ PII	QI	QI	II

61000 xxxx

1	1000	xxxx	0111	xxxx	xxxx	xxxx fault in MC or SR
2	1000	xxxx	0111	xxxx	xxxx	xxxx fault in MC or SR
3	1000	xxxx	0111	EEEE	1000	EEEE I invalid because of
						switchover time in modu
4	1000	xxxx	0111	xxxx	1000	EEEE fault in MC or SR
5	1000	xxxx	0111	xxxx	1000	EEEE fault in MC or SR
6	1000	xxxx	0111	EEEE 1000		EEEE no fault in MC or SR
		1000	EEEE	0111
Legend:
QI	Output image
II	Input image
MC	Master call
PIQ	Process image of the outputs
PII	Process image of the inputs
SR	Slave response
PLC	Programmable logic controller

Note 1:

The following function blocks (FBs) are available for sequence control:

•FB 21 (E16-2433) for the AS-Interface master CP2433 (S5-95 U)

•FB 22 (E16-2430) for the AS-Interface master CP2430 (S5-115 U)

•FC 22 for S7

At least 30 ms must elapse between two function block calls for a module to ensure that the switching status of the inputs can be reliably read.

Note 2:

Programming examples can be requested from out Technical Support, Tel. (+49 91 31) 74 38 33, or down- loaded from the Internet:

Additional information is available from in the Internet under:

http://www.siemens.de/as-interface

The example shows that the output image and input image are not consistent in the master and slave until six AS-Interface cycles have elapsed. The PLC cycle is not synchronous with the AS-Interface cycle. For this reason, the time that must elapse be- fore the output image and input image of the master and PLC are consistent is extended by one AS-Interface cycle and one PLC cycle respectively.

Formula for the cycle time:

4 · ((6 · 5 ms) + 5 ms + 10 ms) =180 ms

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Siemens IK PI · 2004