Control Techniques UD70 User Manual page 70

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