Maxcess Magpowr COMMKIT-DN, Инструкция по эксплуатации, Страница: 2 / 10

Message Structure
DeviceNet Profibus-DP Ethernet IP
message_ID UINT Unsigned16 16-bit unsigned integer
parameter_ID UINT Unsigned16 16-bit unsigned integer
read/write_control UINT Unsigned16 16-bit unsigned integer
parameter data - unsigned short UINT Unsigned16 16-bit unsigned integer
parameter data – integer DINT Integer32 32-bit signed integer
parameter data – float REAL Float 32-bit IEEE 754 single floating-point
Offset Field Length
Beginning of Input/Output area: 0x00 message_ID 2-bytes
0x02 parameter_ID 2-bytes
0x04 read/write_control 2-bytes
0x06 parameter data – unsigned short 2-bytes
0x08 parameter data – integer 4-bytes
0x0C parameter data – float 4-bytes
Read/write control
0x0000 = Read, read data from Cygnus
0x0001 = Write, write data to Cygnus
Read Message
To read a parameter from the Cygnus, the programmer fills in the message_ID, parameter_ID, and sets
read/write_control to READ. The Cygnus responds with a message which has the same message_ID. The
parameter_ID of the response is the same if there were no errors, otherwise the parameter_ID contains the error
number. The read/write_control of the response is set to WRITE. The appropriate data field of the response
contains valid data if there were no errors.
Write Message
To write a parameter to the Cygnus, the programmer fills in the message_ID, parameter_ID, sets
read/Write_control to WRITE, and fills the data field appropriate for the parameter. The Cygnus responds with a
message which has the same message_ID. The parameter_ID of the response will contain an Acknowledge code
if the write was accepted by the Cygnus, otherwise it will contain an error code. The read/write_control of the
response is set to WRITE.
Fieldbus Message Examples
Example: Read the RollWidth (parameter number 47)
Fieldbus sends read message:
message_ID =
1
parameter_ID = 47
read/write_control = 0
data - unsigned short = undefined
data
- integer = undefined
data - float = undefined
Cygnus Normal response:
message_ID =
1
parameter_ID = 47
read/write_control = 1
data - unsigned short = undefined
data
- integer = undefined
data - float = RollWidth value