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Special wiring considerations: Use the following chart for interfacing the pump’s serial communications port to either a 25-pin
or a 9-pin COM port on an IBM-PC type computer.
Pump (RJ11)
Signal
IBM (DB25)
a
IBM (DB9)
b
1, 6
Ground
7
5
2
DSR
20
4
3
RXD
2
3
4
TXD
3
2
5
DTR
6
6
a
Jumper pins 4, 5, and 8 on DB25.
b
Jumper pins 1, 7, and 8 on DB9.
Part Description
Part Number
Modular Cable
12-0677
Adapter RJ-11 to DB9
12-0672
Adapter RJ-11 to DB-25
12-0671
A.1.2 Hand-Shaking
The pump uses hardware handshaking. The pump will not transmit on the TXD output if the DSR input is at a low logic level.
And, the pump will not receive on the RXD input when the DTR output is at a low logic level. A low logic level is -3.0 to -15
volts and a high logic level is 3.0 to 15 volts.
A.1.3 Command Interpreter
The pump’s high-level command interpreter receives and responds to command packets. The pump will not send a message
except when prompted, and it will send a response to every valid command as described below. The response to an invalid com-
mand is “Er/”.
Each command is characterized by a unique two-letter command code, and only one command can be issued per line. Case is
not important; that is, the command codes “PR” “Pr” “pR” and “pr” are all equivalent. Response strings sent by the pump are ter-
minated by the “/” character.
If the pump’s response is “Er/”, send a “#” to clear any characters which may be remaining in the command buffer. The pump
will automatically clear all characters in the command buffer after one second elapses from the time at which the last character of
an incomplete command was sent.
The command packets are as follows:
Command Response
Comments
RU
OK/
Sets the pump to the RUN state.
ST
OK/
Sets the pump to the STOP state.
FLxxx
OK/
Sets the flow rate to x.xx or xx.x mL/min. where the range is fixed for the
pump head size, i.e., for 0.01 to 9.99 mL/min. xxx = 001 to 999, for 0.1 to 39.9
mL/min. xxx = 001 to 399.
FOxxxx
OK/
Sets the flow rate to xx.xx or xxx.x mL/min. where the range is fixed for the
pump head size, i.e., for 0.01 to 10.00 mL/min. xxxx = 0001 to 1000, for 0.1 to
40.0 mL/min. xxxx = 0001 to 0400.
FMxxxx
OK/
Sets the flowrate to x.xxx mL/min., i.e.,
for 0.001 to 9.999mL/min. xxxx = 0001 to 9999.
for 10.00 to 12.00mL/min. xxxx = 1000 to 1200.
PR
OK,x/
Reads the pump’s current pressure, where:
(x, xx, xxx, or xxxx)
x, xx, xxx, or xxxx = current pressure in psi
