Funk-Electronic Piciorgros GmbH
TGW-100/TGW-100R
V2.71 - Page 27 of 59
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Data Communication over TETRA Networks
The TGW-100 can transfer data between any of its wired data interfaces (serial and
Ethernet ports) on one side, and the TETRA infrastructure on the other. The TGW-100
can handle any of the common industrial automation and instrumentation protocols
(MODBUS, MODBUS/TIP, IEC-60870-5-101, IEC-60870-5-104, PakBus, DNP3
etc.…), custom protocols, and configuration data.
Data communication is possible in two modes (of which two are supported presently):
SDS based data transfer:
With SDS based data communication, the TGW-100 can transfer data in serial data
packets of up to 1460 bytes each. The final maximum length of a serial data packet is
determined by the maximum length of a single SDS, which can be limited by the
infrastructure. As a maximum of 7 single SDS can be used for one data packet, the size
limitation will be 980 bytes in networks with a limitation of 140 bytes per SDS, going
up to full 1460 bytes in networks which supports the full specified length of 254 bytes
per SDS.
The packets are broken down if necessary (transparent to the user) into smaller SDS
data blocks. Serial data communication protocols such as MODBUS, DNP3 or IEC-
60870-5-101 are smart routed to the slave modems. To do this, the TGW-100 extracts
the logical addresses, looks up a routing table, and sends the data onward to the
slave/receiving station modem with corresponding ISSI address.
The maximum length of an SDS data block is configurable up to 254 characters.
Restriction of SDS data block length is necessary because not all TETRA infrastructures
support the full length of 2047 bit. If the data block to be transferred is longer than the
maximum SDS length supported form the Tetra infrastructure, it is split into several
SDS data blocks by the transmitting TGW-100 and automatically re-assembled by the
receiving TMO-100 and vice versa.
Setting the SDS parameter
SDS based transmission will require that the proprietary protocol of the TETRA
infrastructure manufacturer must be supported by the TGW-100. Please contact
Piciorgros for a list of supported infrastructures.
