Varec 8300 series, Installation And Operation Manual, Page: 30 / 150

Software Description Tank Gate Interface
20 Installation and Operations Manual
4.1.4 Communications
There are two communications tasks - one for each of the communication channels. COM ports
0 and1 are used to interface to external devices or host systems. Refer to the Hardware Chapter
for the location of these ports.
Note COM1 is not available on the 8315 Tank Gate Interface.
COM0 and COM1
COM 0 and 1 can be configured for communications to Host systems using a variety of
protocols. For COM 0 and 1 the communication interfaces include the following:
•
RS-485 for use in multi-drop configurations or long cable runs (or both)
•
RS-232 for flexibility in configuring other types of communications links such as radio and
fiber optic interfaces
•
RTS/CTS lines are available for hardware handshaking.
4.1.5 Protocols
The Tank Gate Interface is fully compatible with FuelsManager® software. It is also compatible
with a variety of other Host systems including through Modbus protocol.
•
RS-485 for use in multi-drop configurations or long cable runs (or both), with an RS232-
to-RS485 converter.
•
RS-232 for flexibility in configuring other types of communications links such as radio and
fiber optic interfaces.
The default communication settings for the COM ports are as follows:
Note COM1 is not available on the 8315 Tank Gate Interface.
4.1.6 Data Scanning Task
The Data Scanning Task is dedicated to the scanning of field input data from tank gauges. The
input data is stored in arrays that are subsequently accessed by the Point Executive.
4.1.7 Database Manager
The Database Manager is a collection of programs and data. The Database Manager allows the
Tank Gate Interface system executive to access data from the database in an organized and
program-independent manner. It resides in non-volatile RAM.
The Database Manager also contains a Database Dictionary. This dictionary describes how the
database is organized and also provides information describing how data should be presented
to the operator.
After power-up or system reset, a CRC verification of each point in the database is performed.
If the CRC does not have a match for the point, then it is disabled and a flag is set indicating
that the point is invalid.
COM Port Protocol Baud Rate Data Bits Parity Stop Bits
COM0 RTU Slave or Modbus
- Auto-sensing
9600 8 N 0
COM1 Modbus 9600 8 N 0