IEC 62453-309 pdf download Field device tool (FDT) interface specification – Part 309: Communication profile integration – IEC 61784 CPF 9
5.2 DTM services to access instance and device data The services InstanceDataInformation and DeviceDataInformation shall provide access to at least to all parameters of the Universal and Common Practice commands (as far as the device supports the function). Furthermore, the Response Byte 0 and the Response Byte 1 for each command shall be exposed. The services InstanceDataInformation and DeviceDataInformation may also provide access to device specific parameters (e.g. diagnostic information).
6 Protocol specific behavior
6.1 Overview There is only one protocol specific sequence defined for IEC 61 784 CPF 9:
• burst mode subscription.
This sequence explains how the sequence “”, defined in Part 2 of this standard, is applied in context of burst telegrams as defined by IEC 61 784 CPF 9. 6.2 Burst mode subscription A subscription to device initiated data transfer can be requested by sending a transaction request with SubscribeRequest content (see Figure 2). The Communication Channel may detect if the device is already in burst mode. NOTE In HART 5 this can be detected only when burst frames are received from the device. In HART 6 the burst mode can be detected using command 1 05.
The Communication Channel answers to a SubscribeRequest with a SubscribeResponse content.
If burst frames are received, the device is in burst mode and burstModeDetected value is set to TRUE. This means that Device DTM will start to receive burst messages via the transaction response mechanism. In the case that no burst messages were received, burstModeDetected value is set to FALSE. It is up to Device DTM to set device into burst mode. Then Device DTM may call a transaction request with SubscribeRequest content again in order to receive burst messages. In order to unsubscribe, the Device DTM sends a transaction request with a UnsubcribeRequest. The Communication Channel answers with a SubscribeResponse where burstModeDetected value is set to FALSE.
The Device DTM will not receive any more burst information via the transaction response mechanism. The Communication Channel does not switch off the burst mode in the device. The Device DTM may switch burst mode on or off by using normal transaction requests (command 1 09). This is independent of the subscription.
7 Protocol specific usage of general data types
The following table (Table 2) shows how general data types, defined in IEC 62453-2 within the namespace ‘fdt’, are used with HART devices.
8 Protocol specific common data types
9 Network management data types
The data types specified in this subclause are used in the following services:
• NetworkManagementInfoRead service;
• NetworkManagementInfoWrite service.