3.1 Import DBGW Add-On into Logix Designer

1. Import DBGW Add-On instruction #

1.1 If DBGW has to be imported into a running PLC (stopping not allowed)

First: Create a temporary PLC-program for importing and adjusting the different Data types, by following the guide below.

Second: Export DBGW Add-On Instruction and import into running PLC.

1.2 Right click on Add-On Instructions and select “Import Add-On Instruction”

1.3 Browse to your unzipped folder location for DBGW-Service, and select DBGW, and click on Open

1.4 Click on “Data Types”, see screenshot below

1.5 Click on “OK” for confirming default tag names.

1.6 The following UDTs are created

1.7 Double click on “DBGW_DB”. Enter array length for maximum number of records that can be received from database. Click “OK”

1.8 Enter array length for DINTs, REALs & Strings.

Creates the lay-out for all records, used for all queries (Selected, Updated, Inserted and Deleted and executing Stored Procedures)

According to datatypes for used SQL table columns, see below

SQL DatatypePLC datatype
VarcharString
NVarchar (PLC only supports Non Unicode (1 byte characters), Unicode are not supported (2 bytes for special characters)String
CharString
NChar (PLC only supports Non Unicode (1 byte characters), Unicode are not supported (2 bytes for special characters)String
DatetimeString
UniqueidentifierString
TinyIntDINT
SmallIntDINT
IntegerDINT
BigInt (PLC only supports from -2147483648 to 2147483647)DINT
Float (PLC only supports Single-precision floating-point format, 4 byte)REAL
Real (PLC only supports Single-precision floating-point format, 4 byte)REAL
Decimal (PLC only supports Single-precision floating-point format, 4 byte)REAL
Numeric (PLC only supports Single-precision floating-point format, 4 byte)REAL
MoneyREAL
BitBOOL

1.8 Open Data Types for Strings and double click on “DBGW_strColumn. Change “Maximum Characters”, to fit table column datatypes that are converted to PLC-strings

1.9 Double click on “DBGW_strRead”.

Only change “Maximum characters” if PLC/Ethernet module doesn’t support 1460 bytes/TCP-packet.

Note: 1756-EWEB only supports 484 bytes/TCP-packet

1.10 Double click on “DBGW_strWrite”.

Enter “Maximum characters” to fit length of longest SQL query.

Note: 1756-EWEB only supports 462 bytes/TCP-packet

1.11 Double click on “DBGW_strMaxRecord”

Enter length of longest record, to be received or send. This value has to be greater or equal to the value for DBGW_strRead and less than 4096.

Note: If DBGW_strMaxRecord is less than DBGW_strRead a stop of the PLC can occur.

1.12 Import and adjustments completed. DBGW ready to be used in PLC programs.