Toshiba RS485, VF-AS1 Series Appendix 3 Compatibility with the communication function, VF-A7

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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	VF-A7 series	VF-AS1 series	Reference
Item
32-bit mode	For some parameters, including accel-	32-bit mode is not available. For all	Refer to
	eration/deceleration time parameters,	parameters, access is made in 16-bit	Section 9.
	data communication are carried out in	mode.
	32-bit mode.
Handling of negative	Access is made in 32-bit mode.	Access is made in 16-bit mode. To	－
data specified with pa-		see if the value specified with a
rameters		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	No frame can be divided into smaller	Refer to
	smaller frames if all the frames can be	frames. Do not place an interval cor-	Section
	sent within approx. 0.5 sec.	responding to less than 1.5 bytes of	3.1.
		data between frames to be sent.
Communication time-	0.5 sec.	0.1 sec.
out period (guide)
Receipt information in	Even if there is receipt information in	A frame must always begin with a start
front of the start code	front of the start code of a frame re-	code, otherwise it will be rejected.
	ceived, the frame is assumed to begin
	with the start code.
Reset command	When an inverter receives a reset com-	When an inverter receives a reset	Refer to
	mand, it sends back a response before it	command, it sends back no response.	Section
	is reset.		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.

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