Varec TankGate Interface 8315 Series User Manual
Page 47

8315 TGI
Software Description
Varec, Inc.
37
Application
The MODGW point provides status information for the communications with any Modbus
masters used with the 8300 series Tank Gate Interface. On the 8300 series Tank Gate Interface
Motherboard, the MODGW point is created automatically whenever the Modbus Slave protocol is
defined for a COM point. The point number created will correspond to the ComPort such that
MODGW.1 is created for COM 1. Use the Upload command from the Config Menu to retrieve the
data from the MODGW point or any other points created automatically by the RTU.
The MODGW point provides information about the current command and data address
requested by the Modbus master system. The MODGW provides assurance that requests are
being received and processed.
Configuration Parameters
Function
ID
Slave Address that the Modbus Slave protocol handler will respond to. The
default is to match the Unit Address of the 8300 series Tank Gate Interface.
Mode
Operational Mode. The Mode is a hex value, with individual bits controlling
various aspects of the operation of the Modbus Slave protocol handler. The
bits have the following meanings:
0x01 – Set Param Indexing mode
0x02 - Integer Swap mode
0x04 – Swap CRC bytes
0x08 - ASCII mode
0x20 – Wonderware Mode
0x80 - Ignore any trailing nulls in the request
The default is 0.
BaudRate
Baud Rate for communications to the Host system. Valid values are: 1200,
2400, 2400, 9600 and 19200. Changing the BaudRate parameter will
immediately change the configuration of the ComPort.
ComParams
Defines the number of data bits and the parity used by the com port. Valid
values include:
8N - 8 data bits, No parity
8O - 8 data bits, Odd parity
8E - 8 data bits, Even parity
7O - 7 data bits, Odd parity
7E - 7 data bits, Even parity
The default is ‘8N’.
DetectTime
Modbus RTU Mode character timer (in 1/100s of a second).
Dynamic Parameters
Function
Message
Current request message, displayed in hex format.
Command
Current command. Values include:
1 - Read Output Status
2 - Read Input Status
3 - Read Output Registers
4 - Read Input Registers
5 - Force Single Coil
6 - Preset Single Register
15 - Force Multiple Coils
16 - Preset Multiple Registers
Addr
Data Address for current request.
Elapse
Time of the last request from the master
PntCheckSum
CRC-16 Checksum of point's static Configuration Parameters