System information

General Reference Guide IO Servers Configuration
RG-001-0-EN ver 1.5 eWON® - 20/03/2009 - ©ACT'L sa Page 127
5.12.3 Tag name convention
The Item Name can contain the PLC address where the value is polled, or not. If the address is also specified at the topic level, the address
specified at Tag level will be ignored.
5.12.3.1 Value Name
The syntax is the following:
<Memory Type><Modifier><address>
Important: All the addresses are always in BYTES (except for Counter and Timer that are objects)
Note: The Modifier can by omitted, the modifier in bold will be used (DB type must have a modifier).
(*) Important: See “Tags are stored as Float” on page 67
IO Server Name S73&400
Topic Name
A
B
C
Item Name
ValueName, Global Device Address PLC address is defined Tag by Tag
ValueName Topic PLC Address is used.
Table 99: S73&400 IO server - Tag name convention table
Symbol Memory Type Modifier Address
DBx Data Block number x B, C, W, S, D, L, F Byte offset
M Internal Memory B, C, W, S, D, L, F Byte offset
C Counter W, S Object number
T Timer W, S Object number
I Discrete Inputs B, C, W, S, D, L, F Byte offset
Q Discrete Outputs B, C, W, S, D, L, F Byte offset
PI Peripheral Inputs B, C, W, S, D, L, F Byte offset
PQ Peripheral Outputs B, C, W, S, D, L, F Byte offset
Table 100: S7 300-400 Memory types
Symbol Modifier value range
B Byte 0 .. 255
C signed Byte -128 .. 127
W Word 0 .. 65535
S signed Word -32768 .. 32767
D DWord 0 .. 4294967296 (*)
L signed DWord -2147483648 .. 2147483647 (*)
F Float +/- 3.4e38
Table 101: S7 300-400 Modifiers