JVL MAC00-EC4, User Manual

Page: 164 / 300

164 JVL Industri Elektronik A/S - User Manual - Ethernet for MAC and MIS motors
7.2 Commissioning
If an error is detected in the received request an exception frame is returned.
| -
MBAP Header
- | -
Function Code
- | -
Exception code
- |
The returned function code, in case of an exception, is the transmitted function code
with bit 7 set (means that 0x03

0x83, and 0x10

0x90, and 0x17

0x97).
Exception codes
(0x03) Read Holding Registers
Read of registers. Max. 124 x 16bit registers at a time (=62 x 32bit registers). Only even
no. of 16bit registers is supported. The response time is increased slightly for every reg-
ister added. See Minimum poll time, page 166 for minimum poll time.
Request:
Response:
Example, read of module register 3 (= IP address = 192.168.100.1 =
0xC0.0xA8.0x64.0x01):
Request -
|0x00|0x01|0x00|0x00|0x00|0x06|0x01|0x03|0x80|0x06|0x00|0x02|
Response – (Note the byte order!)
|0x00|0x01|0x00|0x00|0x00|0x07|0x01|0x03|0x04|0x64|0x01|0xC0|0xA8|
Possibly exception responses: 0x02, 0x03.
For further documentation see “Modbus_Application_Protocol_V1_1b.pdf” and “Modbus_Mes-
saging_Implementation_Guide_V1_0b.pdf” found on www.modbus.org .
Please notice: Even though all registers is transmitted as 32 bit, some of them
originally derive from 16 bit in the case of MAC050-141. In those situations it
is necessary to interpret them as 16 bit to get the sign correct.
0x01 Function code not supported
0x02 Not allowed register no.
0x03
Too many registers or uneven no. of registers, as every register in motor/module is 32 bit
and requires 2 x 16 bit modbus registers.
7 bytes 1 byte 2 bytes 2 bytes
MBAP header Modbus Cmd.
(0x03) Motor register no. x 2 or module
register no. x 2 + 0x8000 Register count
7 bytes 1 byte 1 byte 2 bytes 2 bytes
MBAP header Modbus Cmd. (0x03) Data byte count Register value low 16bit Register value high 16bit
!