© Edwards Limited 2009. All rights reserved.
Page 35
Edwards and the Edwards logo are trademarks of Edwards Limited.
Installation
B800-00-880 Issue A
condition and will decelerate to rest. To clear this fail condition, you must re-activate the Serial Enable and send a
Serial Stop command.
3.7.3
Serial protocol
The Serial Interface link is set to 9600 Baud, 8 bits, 1 stop, no parity with no handshaking. The commands are made
up from printable ASCII characters. The maximum message size you can send is 80 characters, including start and end
characters.
Note:
All alphabetical characters must be sent in upper case format. Response may contain lower case characters.
Every complete command message you send will receive a response - either a status code or a data return. The nEXT
pump can only deal with one message at a time. It will only accept a new message once the response to the previous
message has been returned.
If the nEXT pump receives characters that are not framed inside start and stop characters, it will ignore them.
Messages with the stop character missing will be discarded with no response when a new start character is received.
If the nEXT pump receives an unrecognisable message between the start and stop characters, it will return an
appropriate error message.
for more information about operating the nEXT pumps in multi-drop mode.
Figure 14 - Conceptual diagram for multi-drop connection using RS232 interface
1
RS232 interface on control equipment
3
nEXT pump
2
Buffer
4
OR gate
Summary of Contents for nEXT240
Page 2: ......
