Siemens KS7 Series Specifikace stáhnout pdf (Strana 112)

Communications Mode CP 523

Initiation conflict

If one partner in the link replies to a line bid (STX character) from the other link partner with STX

instead of DLE or NAK, the result is an initiation conflict, i.e. both link partners want to transmit.

The low-priority partner retracts its line bid and sends DLE. The high-priority partner sends its data

as described above. Following connection cleardown, the low priority partner can send its data.

The Priority parameter is set when initializing parameter block 7 in 3964R mode. Make sure that

one link partner is assigned high priority and the other low priority.

Example for resolving an initiation conflict:

Figure 7-4. Resolving an Initiation Conflict

CP 523

3964(R) mode

Low priority

Link partner

High priority

STX

1st character

nth character

DLE

ETX

BCC*

DLE

* BCC in 3964R mode only

STX

1st character

DLE

STX

7-6

EWA 4NEB 811 6044-02a

1 2 ... 107 108 109 110 111 112 113 114 115 116 117 ... 256 257

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Siemens KS7 Series Specifikace Strana 112