Exceptions; Device Compatibility Parameters; Parameter Over Range During Block Write Fc16; Parameter Over Range During Block Read/Write Fc23 - Control Techniques unidrive sp Advanced User's Manual

Parameter Keypad and Parameter
structure display
Writes when actual parameter type is different from
selected
The slave will allow writing a 32 bit value to a 16 bit parameter as long as
the 32 bit value is within the normal range of the 16 bit parameter.
The slave will allow a 16 bit write to a 32 bit parameter. The slave will
sign extent the written value, therefore, the effective range of this type of
write will be ±32767.
Examples, if #20.1 has a range of ±100000, and #20.2 has a range of
±10000.
Start Number
Write register of 16bit
address registers
#20.1 200 1
#20.1 200 1
#20.1 16584 2 0x00001234
#20.2 201 1
#20.2 16585 2 0x00000123
7.2.10

Exceptions

The slave will respond with an exception response if an error is detected
in the master request. If a message is corrupted and the frame is not
received or the CRC fails then the slave will not issue an exception. In
this case the master device will time out. If a write multiple (FC16 or
FC23) request exceeds the slave maximum buffer size then the slave
will discard the message. No exception will be transmitted in this case
and the master will time out.
Exception message format
The slave exception message has the following format.
Byte
0 Slave source node address
1 Original function code with bit7 set
2 Exception code
3 CRC LSB
4 CRC MSB
Exception codes
The following exception codes are supported.
Code
1 Function code not supported
Register address out of range, or request to read too many
2
registers

Parameter over range during block write FC16

The slave processes the write block in the order the data is received. If a
write fails due to an out of range value then the write block is terminated.
However, the slave does not raise an exception response, rather the
error condition is signalled to the master by the number of successful
writes field in the response.

Parameter over range during block read/write FC23

There will be no indication that there has been a value out of range
during a FC23 access.
7.2.11 CRC
The CRC is a 16bit cyclic redundancy check using the standard CRC-16
polynomial x16 + x15 + x2 + 1. The 16bit CRC is appended to the
message and transmitted LSB first.
The CRC is calculated on ALL the bytes in the frame.
Unidrive SP Advanced User Guide
Issue Number: 7
Parameter Advanced parameter
x.00 description format descriptions
Data Comments
Standard 16 bit write to a
0x1234 32bit register. Value
written = 0x00001234
Standard 16 bit write to a
0xABCD 32bit register. Value
written = 0xFFFFABCD
Value written =
0x00001234
0x0123 Value written = 0x0123
Value written =
0x00000123
Description
Description
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Serial comms
Macros
protocol
7.2.12

Device compatibility parameters

All devices have the following compatibility parameters defined:
Parameter
Device ID Unique device identification code
Minimum slave response
time
When global addressing, the master
Maximum slave response must wait for this time before issuing a
time new message. In a network of devices,
the slowest time must be used
Maximum baud rate
If this data type is not supported then an
32bit float data type
over range error will be raised if this data
supported
type is used
Maximum buffer size Determines the maximum block size.
Electronic Feature look-
Performance
nameplate up table
Description
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