Edwards nEXT nEXT85 - Mixed Parallel and Serial Operation

Reply = v 8 5 2 sp d d d d ; h h h h h h h h cr
Note:
The second return number is a 32 ‑ bit system status word (set of 8 hexadecimal
characters) which is useful for fault nding. Refer to Fault nding on page 86.
6.5 Mixed parallel and serial operaon
In mixed parallel and serial operaon the pump can receive commands from serial and
parallel interfaces. Refer to Figure: Logic interface connecon - mixed parallel and serial
operaon on page 55 to understand how the commands control the pump. The pump
will power up with ‘None in Control’. From this state a parallel start signal or a serial start
command can be received, which can move the pump to parallel control mode or serial
control mode. Serial start commands can be received only if the serial enable line is
acve.
The state of the serial enable line can be switched between acve and inacve while in
mixed parallel and serial operaon. The primary funcon of the serial enable line is to
enable the serial link. It has no direct eect on the control mode. The pump will receive
and respond to serial commands whenever the serial enable line is acve. The pump will
not receive or respond to serial commands when the serial enable line is inacve.
Availability of the parallel standby and fail signals depends on the state of the serial
enable line and the posion of the RS485/RS232 switch as given in Table: Serial enable
matrix on page 76.
Table 25
Serial enable matrix
Switch Serial enable acve Serial enable inacve
RS232
Standby and fail lines are used for
RS232 data.
Standby and fail lines are used for
parallel Standby control and fail
indicaon.
Parallel standby control and fail
indicaon are disabled.
Serial communicaons are disabled.
RS485
Standby and fail lines are used for
RS485 data.
Standby and fail lines are in (RS485)
high impedance state.
*
Parallel standby control and fail
indicaon are disabled.
Serial communicaons are disabled.
* Pump target speed will switch between run speed and standby speed in response to
data driven onto the RS485 bus by other devices connected to the bus. It is not
recommended to acvate the parallel start line with the RS485/232 switch in RS485
posion and serial enable Inacve. Deacvaon of the serial enable line is not
recommended with the pump running following a start from the parallel start line when
the RS485/232 switch is in the RS485 posion.
In parallel control mode, the pump does not accept serial stop commands but will
accept all other serial commands. When serial enable is acve, the pump will operate at
standby speed if the serial standby command is given.
The pump will operate at standby speed when:
▪
Serial enable is inacve
Page 76
B8G000880_D - Operaon