B800-00-880 Issue A
Page 34 © Edwards Limited 2009. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Installation
selected, some additional hardware will be required to link several nEXT pump units to a single serial link master. A
concept drawing of one possible arrangement is shown in Figure 12a. Conversely when the RS485 option is selected,
connecting several nEXT pumps to a single master becomes a simple wiring exercise as shown in Figure 13.
Figure 12 - Logic interface connections - serial mode
Figure 13 - Logic interface connections - RS485 serial mode
3.7.2 Serial enable
To send a Serial message you must first activate Serial Enable. This is achieved by linking the Serial Enable input
signal (pin 5) to pin 2 of your logic interface mating half. We recommend that you incorporate this link into your
Serial communications cable so that the Serial Enable is only activated when the serial cable is connected. When you
subsequently remove the cable, Serial Enable will become inactive.
Serial Enable acts as an interlock for commands sent over the Serial Interface. If the pump is running (having been
sent a Serial Start command) and the Serial Enable subsequently becomes inactive, the pump will trigger a fail
1. RS232 interface on control equipments
2. 24-48V d.c. electrical supply
3. Fuse
4. nEXT pump logic interface
1. RS485 interface on control equipments
2. 24-48V d.c. electrical supply
3. Fuse
4. nEXT pump logic interface
To Next Page
Loading...
Need help?
General
