UD70
Issue code: 70nu2
6-10 Serial communications
The UD70 will respond with a single control character, as follows:
Control Code Meaning
ACK Acknowledge — Message has been understood and implemented.
NAK Message invalid, data is too long or out of range, parameter is invalid, parameter is
read-only, or the BCC is incorrect.
Example
Set parameter Pre-set frequency 1Pre-set frequency 1 at +76.4 for Unidrive (unit 6, group 2) send:
Control Address Control Parameter Data Control BCC
EOT 2 2 6 6 STX 0 1 2 1 + 0 7 6 . 4 ETX 1
Re-writing data
Once a write message which includes the address field has been sent and
accepted with either a <ACK> or <NAK> response, subsequent write
messages to that particular UD70 can use a re-write message structure in
which the address does not need to be re-transmitted. The re-write
structure is as follows:
STX M1 M2 P1 P2 D1 ... Dn ETX BCC
When a different UD70 is addressed, or an invalid character is received, the
re-write facility no longer functions. The first UD70 can be addressed again
only by using the full write message with the address.
Calculating the block checksum (BCC)
The block checksum is calculated by applying an exclusive OR function to all
of the characters of a message after the STX control character.
XOR truth table
ABOut
000
01 1
101
110
For example, the serial command to set Pre-set speed 1Pre-set speed 1 at
–34.5Hz on a Unidrive:
To Next Page
Loading...
Need help?
General
