User`s guide

176
CHAPTER 8 - CFW-08 OPTIONS AND ACCESSORIES
The connection between the networkparticipants is performed
through a pair of wires. The signal levels are according to the
EIA RS-485 STANDARD with differential receivers and
transmitters.You must use the serial communication module
KRS-485-CFW08 (refer to item 8.13).
Whenthemasterisfittedonlywith a RS-232serial interface,you
mustapplya levelconversion module from RS-232toRS-485.
In this case we have the connection of a master to an inverter
(point to point).The data can be exchanged in a bi-directional
way, but not simultaneously (HALF DUPLEX).
The logical levels meet the EIA RS-232C STANDARD, that
specifies the use of balanced signals. In this case one wire is
used for thetransmission (TX), one wire for the reception (RX)
and one wire for the return (0 V).This configuration is a three
wire economy model.
You mustuse the RS-232 (KCS-CFW08) module in theinver-
ter (refer to item 8.11).
The items of this section describe the protocol used in the
serial communication.
Parameters: are those existing in the inverters whose
visualization or alteration is possible through the keypad
(HMI)interface.
Variables: are values that have specific functions in the
inverter and thatcan be read and, in some cases,modified
by the master.
8.24.2.2
RS-232
8.24.3
Definitions
8.24.3.1
Used Terms
Other ASCII characters used by the protocol:
ASCII
CODE
DEC
HEX
0
48
30
1
49
31
2
50
32
3
51
33
4
52
34
5
53
35
6
54
36
7
55
37
8
56
38
9
57
39
=
61
3D
STX
02
02
ETX
03
03
EOT
04
04
ENQ
05
05
ACK
06
06
NAK
21
15
Table 8.7
- Others ASCII characters used by the protocol