Data messages

• Data type

• Region number (same as that in the SSI message)

• Component number (same as that in the SSI message)

• Module number (same as that in the SSI message)

• Value number (same as that in the SSI message)

• Subaddress (currently always 0)

• Index: to discriminate between items of data when a message contains several different items of data.

Since the index in the message constitutes part of the peripheral address, this ensures total flexibility in configuring the individual items of data in a message. Hence the each of the items of data can be combined in one data point, say, or they might form part of a larger data point, or else be distributed amongst several data points.

The index numbers for each telegram are assigned in the driver. They are listed separately under the different messages.

In principle there are several options for assigning WinCC OA data points to messages. The peripheral addresses can be configured at the data point nodes, provided the sheets under this node have the same type (i.e. for all dynamic arrays of data points of the same type, such as a bit pattern structure, bit structure), as well as on the sheets. If the peripheral address is configured at a node, then the index number of the peripheral address specifies the object in the message from which the data is distributed to all other objects on the sheets of the WinCC OA data point. Thus one could for instance distribute 16 individual messages (index 0 to 15) to two data points of type bit structure, each with 6 bits, by specifying the index of the peripheral address as 0 in the data point node of the first data point, and as 6 in the node of the second data point. Incoming messages are then distributed to the sheets of the data points. The six sheets of the first data point receive messages 0-5 (bits), and the sheets of the second data point receive messages 6-11 (also bits). Since the remaining messages (12-15) have not been configured to any WinCC OA data point, they are discarded by the driver.

In addition, indices are introduced for some messages for special handling purposes. For instance it ought to be possible to configure the 16 individual messages jointly on one data point sheet of type bit pattern; the index 20 (for 16 individual messages) has been introduced for this purpose.

The data area of the message contains the following elements:

The value is configured to a dedicated data point in WinCC OA. The corresponding type of the WinCC OA variable is natural number.

DF = 02 - Digital value signed 32 Bit ( 31 Bit plus VZ )

The data area of the message contains the following elements:

The value is configured to a dedicated data point in WinCC OA. The corresponding type of the WinCC OA variable is integer.

DF = 03 - Transformer tap position ( digital )

The data area of the message contains the following elements:

It is recommended to configure the three values to a common data point.

DF = 04 - Floating Point

The data area of the message contains the following elements:

The assigned WinCC OA data point is of type floating point.

Table: The indices and types for "floating point" assigned to the individual items of data.

DF = 05 - Combination messages

The data area of the message contains the following elements:

DF = 06 - Computer link formats

The data area of the message contains the following elements:

More precise structuring of the data is not implemented.

DF = 07 - String

The data area in the message consists of up to 1000 bytes of transparent data. Currently up to 57 bytes are supported. More precise structuring of the data is not implemented.

DF = 08 - Transparent data

The data area of the message contains the following elements:

More precise structuring of the data is not implemented.

DF = 09 - 16 individual messages

The data area of the message contains the following elements:

• 2 bytes of invalid bits accompany the message bits

If all the individual messages are mapped onto a bit pattern, the associated invalid bit is obtained from logically ORing the individual invalid bits.

DF = 10 - 8 Double messages

The data area of the message contains the following elements:

This message indicates the state of a switch. Each switch state is described by two bits.

If all the messages are mapped onto a bit pattern, the associated invalid bit is obtained from logically ORing the individual invalid bits.

DF = 11 - 4 Double messages with command feedback

The data area of the message contains the following elements:

This message is used to return information on the effects of a command. 4 bits describe the state of a switch (relays, NC contacts)

If all the messages are mapped onto a bit pattern, the associated invalid bit is obtained from logically ORing the individual invalid bits.

DF = 12 - 1 Individual data point message

The data area of the message contains the following elements:

DF = 13 Command

The data area of the message contains the following elements:

This message constitutes the pulse command of the SSI protocol. It contains a single command. A relay (switch) is switched for the given switching time, and then returns to an idle state. Normally two different command numbers would be required to switch a peripheral device between "ON" and "OFF". Unlike the usual data formats, data points of type pulse command must be signaled to the Event Manager by means of a single registration (in the command direction). All other data points are registered as a group. Provided the peripheral address is configured in the configuration panel then the correct form of registration will be set automatically. If configuration is from ASCII files, however, then the attribute address.._mode must be set to 5 (= single registration) for these commands, and to 1 (in the command direction) or 2 (in the message direction) for all other commands.

The message contains the switching time in addition to the command number. The switching time is coded in a byte, where the individual bits have the following meaning:

The switching time can be specified in two different ways. For most commands it is adequate to use a system-wide switching time that applies to all commands. A default value for the switching time is provided for this purpose in the SSI driver. This can be set using the defaultImpulseTime entry in the configuration file (see chapter on Configuration file entries). If this entry does not appear, then 8 is used by default (equals 100 mS). If other switching times need to be set for individual commands, then these can be specified in the data point _SSI_Impulse_Times (this contains a dynamic array of bit patterns in which the required switching times can be set - the simplest way of doing this is in the Pulse times panel of the Peripheral address panel). In order to then assign a switching time from this array to a command data point, the index for this switching time in the _SSI_Impulse_times data point is added to the peripheral address as an extension to the data type (separated by a colon). One should note that this extra index is only allowed for data points of type command.

Example

The peripheral address 13:2.255.3.4.1.0 assigns to the data point the switching time contained in the second array item of the _SSI_Impulse_Time data point.

For every priority-controlled message there is an equivalent real-time message. This contains a 5-byte time field in front of the data, indicating the time the supplied data was generated. This time information has the following format:

DF = 101 Digital value unsigned 32 Bit with time

This message otherwise has the same action as the analog NEZ message.

DF = 102 Digital value signed 32 Bit ( 31 Bit plus VZ ) with time

This message otherwise has the same action as the analog NEZ message.

DF = 03 - Transformer tap position ( digital ) with time

This message otherwise has the same action as the analog NEZ message.

DF = 104 Floating point with time

This message otherwise has the same action as the analog NEZ message.

DF = 105 Combination message with time

This message otherwise has the same action as the analog NEZ message.

DF = 106 Computer link formats with time

This message otherwise has the same action as the analog NEZ message.

DF = 107 String with time

This message otherwise has the same action as the analog NEZ message.

DF = 108 Transparent data with time

This message otherwise has the same action as the analog NEZ message.

DF = 109 16 Single messages with time

This message otherwise has the same action as the analog NEZ message.

DF = 110 8 Double messages with time

This message otherwise has the same action as the analog NEZ message.

DF = 111 4 Double messages with command feedback with time

This message otherwise has the same action as the analog NEZ message.

DF = 112 1 Single data point message with time

This message otherwise has the same action as the analog NEZ message.

DF = 113 Command with time

This message otherwise has the same action as the analog NEZ message.