Edwards nEXT 55, Instruction Manual

Page: 52 / 116

4.6.3 Serial protocol
The serial interface link is set to 9600 Baud, 8 bits, 1 stop, no parity with no
handshaking. The commands are made from printable ASCII characters. The maximum
message size that can be sent is 80 characters, with start and end characters.
Note:
All alphabetical characters must be sent in upper case format. The response can have
lower case characters.
Each complete command message sent will receive one of the responses: a status code
or a data return. The pump can only process with one message at a time. The nEXT
pump will only accept a new message when the response to the previous message has
been returned.
If the pump receives characters that are not framed in the start and stop characters, the
pump will ignore them. Messages with the missing stop character will be discarded with
no response when a new start character is received. If the pump receives an
unrecognisable message between the start and stop characters, it will return an
applicable error message.
Refer to
Multi-drop operation on page 56 for more information about how to operate
the pump in a multi
‑
drop mode.
4.6.4 Command set
Table 22
Summary of commands that can be sent to the pump
Object name
Command Parameter
range
Factory
setting
Data type Units
Comments
Node !S850 0..99 - decimal address Multi-drop address
?850 0 = disable multi-drop ad-
dress
99 = wild card
Pump type ?S851 8 - string chars Pump type
10 - string chars DSP software version
number
4 - string chars (D39659610)
Full speed RPS (1500 for
nEXT 55/85)
Pump control !C852 0 - decimal - Stop the pump
1 Start the pump
?V852 0..1800 - decimal RPS Measured motor speed
32-bits hex flags System status word
Time setting !S854 1..30 8 decimal minutes Timeout period for both
initial ramp up and if
speed decreases below
50%
?S854 - - - - -
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B8G000880_E - Installation