KROHNE ALTOSONIC V Modbus EN - Manual (Page 18)

ALTOSONIC V
ModBus Manual 0300 rev07 E 7.30855.35.00 Page 18 of 64
The transmit order in both modes:
IEEE (1)
40
h
(2)
84
h
(3)
08
h
(4)
00
h
Normal mode (1)
40
h
(2)
84
h
(3)
08
h
(4)
00
h
Reversed mode (3)
08
h
(4)
00
h
(1)
40
h
(2)
84
h
Doubles could be transmitted in two ways:
Example
The double number 4.125000001862645 will give the IEEE representation.
S EXPONENT MANTISSA
0 100 0000 0001 (1)0000 1000 0000 0000 0000 0000 0000 0010 0000 0000 0000 0000 0000
•
A biased exponent of 1025 (401 hexadecimal) is exp. 2
• A positive sign
•
Mantissa = 4 + 1/8 + 1/536870912. Note that the first bit is not stored!
The transmit order in both modes:
IEEE (1)
40
h
(2)
10
h
(3)
80
h
(4)
00
h
(5)
00
h
(6)
20
h
(7)
00
h
(8)
00
h
Normal mode (1)
40
h
(2)
10
h
(3)
80
h
(4)
00
h
(5)
00
h
(6)
20
h
(7)
00
h
(8)
00
h
Reversed mode (3)
80
h
(4)
00
h
(1)
40
h
(2)
10
h
(7)
00
h
(8)
00
h
(5)
00
h
(6)
20
h
6.4 Maximum requested points
The maximum points in a single request depend on the type of data.
Data type Modicon compatible mode
(count on 16 bit registers) Not Modicon compatible mode (count on
type)
Boolean 2000 2000
Integer 125 125
Long integer 124 62
Float 124 62
ASCII 124 62(8chars) 31(16 chars)
Double 124 31
How to set up a redundant system
Two or more UFP-V systems
If one or more UFP-V systems are used with one host system, the host system must support Modbus
master mode. The UFP-V will then operate in Modbus slave mode.
Two or more host systems
As a result of operational safety, some applications require more than 1 host-system communicating
with one UFP-V.
If the UFP-V is used in slave mode, only one host-master may be connected.
One solution is to use the UFP-V as a Modbus master. Now the data is sent to the first addressed host
(first poll block), the second poll block sends the data to the next host.
The data could be different, because the measured data is updated.