Filter
Top Products
E6581315
69
Appendix 3 Compatibility with the communication function
of the VF-A7
To provide consistency in communication procedures, the communication function of the VF-AS1
series of inverters has been designed based on the protocols used for the Toshiba VF-A7 series of
inverters. With regard to compatibility, however, VF-A7 users should check the items described be-
low before using the communication function of their inverters.
To VF-AS1 inverter users:
Some parameters of the VF-A7 are different from those of the VF-AS1 in function or adjustment
range (upper and lower limits), even though they have the same title or the same communication
number. So, when accessing a parameter, consult the VF- A7 inverter’s instruction manual to see if
the parameter is identical to the corresponding parameter of the VF-AS1. If the parameter differs,
modify the computer program to suit your inverter. To avoid hazards, never copy parameters from
one model of inverter to another.
Comparison of communication-related items
The table below gives a comparison of communication-related items to be kept in mind when re-
placing VF-A7 inverters with VF-AS1 inverters or when connecting VF-A7 inverters and VF-AS1 in-
verters to the same network. It does not cover any items common to the VF-A7 and VF-AS1 series
of inverters.
Model
Item
VF-A7 series VF-AS1 series Reference
32-bit mode For some parameters, including accel-
eration/deceleration time parameters,
data communication are carried out in
32-bit mode.
32-bit mode is not available. For all
parameters, access is made in 16-bit
mode.
Refer to
Section 9.
Handling of negative
data specified with pa-
rameters
Access is made in 32-bit mode. Access is made in 16-bit mode. To
see if the value specified with a
parameter is signed or not, check the
adjustment range of the parameter.
Division of a frame A frame can be sent with it divided into
smaller frames if all the frames can be
sent within approx. 0.5 sec.
No frame can be divided into smaller
frames. Do not place an interval cor-
responding to less than 1.5 bytes of
data between frames to be sent.
Communication time-
out period (guide)
0.5 sec. 0.1 sec.
Receipt information in
front of the start code
Even if there is receipt information in
front of the start code of a frame re-
ceived, the frame is assumed to begin
with the start code.
A frame must always begin with a start
code, otherwise it will be rejected.
Refer to
Section
3.1.
Reset command When an inverter receives a reset com-
mand, it sends back a response before it
is reset.
When an inverter receives a reset
command, it sends back no response.
Refer to
Section
8.1.
RS485 baud rate 1200 to 38400 bps 9600 to 38400 bps Refer to
Section
7.1.
Notice
♦ Do not use communication programs written for another series of inverters.
Even though parameters have the same title and the same communication number, they may be different
in function. When using a parameter, always check its specifications in the instruction manual for your
inverter. If the specifications of the parameter differ, modify the computer program to suit your inverter.
♦ To avoid hazards, do not copy parameters from one model of inverter to another.
Even though parameters have the same titles and communication numbers, they may be different in
function.