ICC ETH-1000, Инструкция по эксплуатации

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11.7.3.3.1 Database Access Tag Reference
Any given database address can be accessed with its own unique tag name with
one PLC instruction. Tag names are generated according to the following
structure:
[target prefix]_[data type]_[address]
Where
[target prefix]
is a 2-character sequence “DB” to indicate database access.
[data type] is a 1-character field that specifies the data type of the values in the
response. Enter “b” or “B” to indicate byte (8-bit). Enter “w” or “W” to indicate
word (16-bit). Enter “d” or “D” to indicate double word (32-bit). Note that the
storage/source element on the requester must also be of the same data size.
[address] is a 1- to 4-character field (“0”, “1”…”4094”, “4095”) corresponding to
the referenced database address. Specify the value in decimal format.
Examples
Access bytes starting at database address 0... .......................... DB_b_0
Access words starting at database address 2048 ...................... DB_w_2048
Access double words starting at database address 4092 ........... DB_d_4092
11.7.3.3.2 ControlLogix Example: Read Database Data
This example program will show how to continuously read a block of data from
the gateway’s internal database with a single MSG instruction. Only one read
request is outstanding at any given time.
1) Create new Tags.
a) Double click “Controller Tags” in the controller organizer view.
b) The “Controller Tags”
window appears.
Refer to Figure 68.
c) Select the “Edit Tags”
tab at the bottom.
d) Create a new tag by
entering “connection”
in the first blank
Name field, and
change its Data Type to “MESSAGE”. This tag will contain configuration
information for the MSG instruction.
e) Select the “Monitor Tags” tab. Expand the “connection” tag by clicking
on the “+” sign next to the tag name. Scroll down to the
connection.UnconnectedTimeout field and change its value from the
default 30000000 (30s in 1uS increments) to 1000000 (1s). This value
Figure 68: Create New Tags