Specifications

Function Block for Siemens 115 U Section 5-10

A write-access to these data types is principally carried out with a coordination ﬂag.

Just like the communications block, the coordination ﬂag must be deﬁned such that

the settings in the terminal and passive device are in agreement.

Part of a program installed in the receiving device, denoted in the PLC as data

handling block, will monitor the coordination ﬂag.

If the coordination ﬂag is set, the data will be processed by the data handling block

in accordance with the ﬁrst 4 bytes in the communications block.

After the data have been processed, the coordination ﬂag will be erased thereby

allowing further transmissions.

5.9 Protocol 3964R - Restrictions

The protocol 3964 allows data comprising a maximum of 128 bytes to be transmit-

ted per message. No further messages are transmitted or processed.

5.10 Function Block for Siemens 115 U

The supplied function block FB186 can be implemented in a Siemens 115 U.

The function block processes data from the terminal which are to be transmitted to

the PLC.

The ﬁrst 4 bytes of the data which are written to the deﬁned communications data

block are interpreted in accordance with the table ”Assignment of Bytes 1-4”.

The function block FB186 supports the following commands from the table ”As-

signments of Bytes 1-4”:

2 Output Byte

3 Flag Byte

11 Output Bit

12 Flag Bit.

When activating the function block, the communications data block and the coor-

dination ﬂag must be speciﬁed as parameter. These parameters must comply with

the settings in the terminal.

The deﬁned communications data block must comprise a size of 128 bytes or 64

data words, respectively.