This topic relates to IEC 60870-5 KEMA PSTN channels. For KEMA compatible devices that communicate via serial or network-connected channels, you need to configure and IEC 60870-5 Channel of the appropriate type (see Configuring an IEC608705 Channel in the Geo SCADA Expert Guide to the IEC 60870-5 Driver).
For each telephone line connection that exists for communications between the Geo SCADA Expert server and the KEMA outstations on your system, you need to configure an IEC 60870-5 KEMA PSTN Channel item in the Geo SCADA Expert database.
You configure the properties of each channel using the fields on the IEC 60870-5 KEMA PSTN Channel Form. The Form has several tabs.
Use the fields on the PSTN Channel tab to:
Use the fields on the Scan Parameters tab to:
- Configure the Scan Parameters— see Defining Scan Parameter Settings for a Channel in the Geo SCADA Expert Guide to Advanced Drivers.
- Specify when Communication Statistics are Updated— see Defining the Communication Statistics Update Rate in the Geo SCADA Expert Guide to Advanced Drivers.
- Specify any Pre- or Post-Ambles— see Defining any Default Pre- and Post-Amble Message Settings for a Channel in the Geo SCADA Expert Guide to Advanced Drivers.
The IEC 60870-5-101 protocol uses the hexadecimal digits 68 or 10 to indicate the start of a message (or hexadecimal E5 if the system uses single character acknowledgments). As such, we advise only using hexadecimal 68, 10, or E5 as a pre-amble where such a character is required by the transmission system and is not seen by the receiving device. Hexadecimal 68, 10, and E5 should not be used for pre- or post-amble ‘padding’.
The fields on other tabs are common to channels on many advanced drivers—for information, see Tabs on Channel Forms in the Geo SCADA Expert Guide to Advanced Drivers.