Data Sheet

ManualsBrandsRoboteQ ManualsSerial DC ControllersRoboteQ GDC3660E 60V 3x180A Brushed DC Motor Controller (w/ Ethernet)

• The request is received without an error, but cannot be processed by the slave for another reason.

The slave replies with an exception response.

Here is an example of an exception response:

0A 81 02 B053

Name

Description

Node address

Function code with the highest bit set.

The exception code.

B0 53

Cyclic redundancy check (CRC-16-IBM)

The exception codes as explained in the Modbus specification are:

Code

Name

Meaning

0x01

Illegal

Function

The function code received in the query is not an allowable action for the

slave. This may be because the function code is only applicable to newer

devices, and was not implemented in the unit selected. It could also

indicate that the slave is in the wrong state to process a request of this type,

for example because it is unconfigured and is being asked to return register

values. If a Poll Program Complete command was issued, this code indicates

that no program function preceded it.

0x02

Illegal Data

Address

The data address received in the query is not an allowable address for the

slave. More specifically, the combination of reference number and transfer

length is invalid. For a controller with 100 registers, a request with offset 96

and length 4 would succeed, a request with offset 96 and length 5 will

generate exception 02.

0x03

Illegal Data Value

A value contained in the query data field is not an allowable value for the

slave. This indicates a fault in the structure of remainder of a complex

request, such as that the implied length is incorrect. It specifically does NOT

mean that a data item submitted for storage in a register has a value outside

the expectation of the application program, since the MODBUS protocol is

unaware of the significance of any particular value of any particular register.

0x04

Slave Device

Failure

An unrecoverable error occurred while the slave was attempting to perform

the requested action.

0x05

Acknowledge

Specialized use in conjunction with programming commands.

The slave has accepted the request and is processing it, but a long duration

of time will be required to do so. This response is returned to prevent a