Omron CS1W-SLK11-21 - 06-2004, Manual

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Data Link Status Section 4-9
4-9-1 Data Link Status
The following status is indicated through the ON/OFF status of each bit. Refer
to
Word Configuration later in this section for specific allocations.
Note (1) The Data Link Active Flag is for checking the data link system. It is not
designed to check for data link errors. To check for data link errors, use
the Data Link Communications Error Flag.
(2) The CPU Unit Run Flag, CPU Unit Error Flag, Data Link Communications
Error Flag, and Data Link Active Flag are valid only if the Local Node Data
Link Active Flag is ON. Be sure to use the Local Node Data Link Active
Flag with an AND condition when using any of these flags in program-
ming.
Item Bits Contents
Node status CPU Unit
Operating
Flag 0, 4, 8, 12 ON if the CPU Unit of the node is operating (RUN or MONITOR
mode).
OFF if the CPU Unit of the node is in PROGRAM mode.
• This flag is invalid if the Data Link Communications Error Flag for
the node is ON.
• If a fatal error (including an FALS instruction) occurs during opera-
tion, this flag will remain ON.
• When using this flag in programming, take an AND of NO condi-
tions of it and the local node’s Data Link Active Flag.
CPU Unit
Error Flag 1, 5, 9, 13 ON if there is a fatal error in the CPU Unit of the node.
OFF when the CPU Unit of the node is operating normally.
• This flag is invalid if the Data Link Communications Error Flag for
the node is ON.
• When using this flag in programming, take an AND of NO condi-
tions of it and the local node’s Data Link Active Flag.
Data Link
Communica-
tions Error
Flag 2, 6, 10, 14 ON if the node has a communications error and is not participating
in the network (if the designated node is not sending data link data,
communications from that node are assumed to be in error).
OFF when the CPU Unit for the node is operating normally (data
link data is being sent continuously from the node).
• To check participation of a node in the data links, take an AND of
a NO condition of this flag and a NC condition of the Data Link
Active Flag.
Data Link
Active Flag 3, 7, 11, 15 ON if the node has participated in the data links, even if only once.
OFF if the node has not yet participated in the data links.
• This bit turns ON once the node has participated in the data link,
and remains ON even if the node is no longer participating (used
to check system startup). Consequently, this flag cannot be used
to check the current participation status of a node in the data
links.
• When using this flag in programming, take an AND of NO condi-
tions of it and the local node’s Data Link Active Flag.
Local node
status Local Node
Data Link
Active Flag Bit 15 of first
allocated
data link +
23 words ON if the node is participating in the data links.
OFF if the node is not participating in the data links.
• If this flag is OFF, local communications will not be operating nor-
mally, so there is no guarantee that the status of other flags will be
correct. Consequently, be sure to use this flag with an AND condi-
tion to check the status of other flags.
Network sta-
tus Startup
Node
Address Bits 8 to 13
of first allo-
cated data
link word +
23 Startup node addresses 1 to 62 are stored as 1 to 3E Hex.