System information

General Reference Guide IO Servers Configuration
RG-001-0-EN ver 1.5 eWON® - 20/03/2009 - ©ACT'L sa Page 92
After the numerical value, the characters F, L, I, D or W can be used to specify how to read the value. The following table describes the different
character meaning.
(*) Important: See “Tags are stored as Float” on page 67
When reading a 32 bits value, two consecutive registers or coils are read and combined e.g. 40001L,11 to access in Long representation the reg
1 on the slave 11.
Reading high 32 bits values involve a lost of precision in the mantissa because internally all the values are considered as float by the eWON.
examples:
STATUS TAG:
The STATUS Tag is a special Tag that returns information about the current state of the communication for a given device. As for other Tags, the
status Tag ItemName is composed of:
Status,Address
If the address is omitted, the Topic address will be used e.g. status,11 points to the status of the slave 11
You can define a status Tag for each address used.
If you use the status MODBUS address, the Tag must be configured as analog:
Character Description
W Reads 1 register considered as 16 bits unsigned integer (DEFAULT IF NOT SPECIFIED)
I Reads 1 register considered as 16 bits signed integer
D Reads 2 regs R1, R2 as a DWORD R1 is Less significant, R2 is most significant (32 bits, unsigned) (*)
E Reads 2 regs R1, R2 as a DWORD R2 is Less significant, R1 is most significant (32 bits, unsigned) (*)
L Reads 2 regs R1, R2 as a LONG R1 is Less significant, R2 is most significant (32 bits, signed) (*)
M Reads 2 regs R1, R2 as a LONG R2 is Less significant, R1 is most significant (32 bits, signed) (*)
F Reads 2 regs R1, R2 as a FLOAT R1 is Less significant, R2 is most significant (32 bits, signed)
H Reads 2 regs R1, R2 as a FLOAT R2 is Less significant, R1 is most significant (32 bits, signed)
Table 61: the characters used to specify how to read the value
address meaning
40001,10 access the Holding Register at address 1 on the UnitID 10
1,11 access the Coil at address 1 on the UnitID 11
+320234,12 access the Input Register at address 20234 on the UnitID 12
40001,100,10.0.0.53 access the Hoding Register at address 1 on the UnitID 100 at IP address 10.0.0.53
40010L,12 access the LONG Holding Register at address 10 (and 11) on the UnitID 12
40008F,15 access the FLOAT Holding Register at address 8 (and 9) on the UnitID 15
Table 62: Modbus address examples
Tag value Meaning
0
Communication not initialized. Status UNKNOWN.
If no Tag is polled on that device address, the communication status is unknown.
1 Communication OK.
2 Communication NOT OK.
Table 63: MODBUS status values