Mitsubishi Electric CR800 Series Ethernet Function Instruction Manual page 33

[Explanation]
(1) This command is used in a combination with the OPEN instruction. The following lists the meanings and values for the
types of the files specified by the OPEN instruction.
Type of file to be
opened
File Indicates whether or not the file has been
opened.
1 is always returned after executing the
OPEN instruction.
Communication line Indicates whether
Ethernet or not connection
is made with the
counterpart.
[Related Instruction]
OPEN
[Related Parameters]
COMDEV, CPRE**, NETMODE
Meaning
For server setting
For client setting
3 Description of functions
Value
1: Already opened.
-1: The file number is undefined (not opened).
1: Client is already connected.
0: Client is not connected.
-1: The file number is undefined (not opened).
1: Already connected to the server. (Connection
has been made.)
0: Not connected to the server. (Connection has
not been made. Equivalent to when the server is
down after being opened.)
-1: The file number is undefined. (When the file
has not been opened, or has been opened
while the server is down.)
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