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
32-bit mode
For some parameters, including accel-
eration/deceleration time parameters,
data communication are carried out in
32-bit mode.
Handling of negative
Access is made in 32-bit mode.
data specified with pa-
rameters
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.
Communication time-
0.5 sec.
out period (guide)
Receipt information in
Even if there is receipt information in
front of the start code
front of the start code of a frame re-
ceived, the frame is assumed to begin
with the start code.
Reset command
When an inverter receives a reset com-
mand, it sends back a response before it
is reset.
RS485 baud rate
1200 to 38400 bps
♦ 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.
VF-A7 series
Notice
69
VF-AS1 series
32-bit mode is not available. For all
parameters, access is made in 16-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.
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.
0.1 sec.
A frame must always begin with a start
code, otherwise it will be rejected.
When an inverter receives a reset
command, it sends back no response.
9600 to 38400 bps
E6581315
Reference
Refer to
Section 9.
−
Refer to
Section
3.1.
Refer to
Section
8.1.
Refer to
Section
7.1.