Omron NX701-1620 User Manual

5 Other Functions
5-18
NJ/NX-series Database Connection CPU Units User’s Manual (W527)
5-4 How to Prevent Losing SQL
Statements at Power Interruption
This section describes how to write the user program so as not to lose the SQL statements at
power interruption.
5-4-1 Overview
You can prevent losing the SQL statements to send and the SQL statements stored in the Spool
memory even if a power interruption occurred during execution of a record processing instruction
(such as DB_Insert and DB_Update instructions) by using the Spool function in combination with
the user program.
5-4-2 Procedures
Use the following procedures.
Checking the Progress of the DB Connection Instruction
The progress of the DB Connection Instructions is output to the SendStatus output variable as
enumeration data. Use this data to create the user program.
Output variable
Meaning
Data type
Description
SendStatus Send
Status
_eDBC_SEND_STATUS _DBC_SEND_INIT(0): Initial status
_DBC_SEND_UNSENT(1): SQL statement unsent
_DBC_SEND_SENDING(2):
Sending SQL statement
_DBC_SEND_SPOOLED(3):
SQL statement spooled
_DBC_SEND_COMPLETE(4):
SQL statement transmission completed
Variable Settings
 Set the Retain attribute of the input parameter (DB Map Variable) of the MapVar input variable
to Retained.
 Set the Retain attribute of the output parameter of the Busy output variable to Retained.
 Set the Retain attribute of the output parameter of the SendStatus output variable to Retained.

Omron NX701-1620 Specifications

General

Brand	Omron
Model	NX701-1620
Category	Controller
Language	English