Publication 5390-001 Revision B
16
Harvard Apparatus Model 33 Twin Syringe Pump User's Manual
Pump Chain Commands
The Pump Chain RS-232 interface is used to enhance the control applications of the
Pump 33. This interface allows all control information to be entered into the pump
from an external source such as a computer. In addition, this interface allows up to
100 Pump 33’s or, in certain cases, other RS-232 devices to be controlled from a single
RS-232 communication port on a computer. Assign each pump in the pump chain a
unique address from 0 to 99. This address is used to identify which pump is to receive
a command and which pump is responding. Configure each pump with its assigned
address and the baud rate being used (See External Control & Interfaces). When a
pump is sent a command, or a request is made for its prompt, the Remote LED on the
display will illuminate, indicating that the pump is receiving pump chain commands.
The LED remains illuminated until the pump is turned off or SET and 1 is entered on
the keypad, indicating a change in the pump chain configuration.
A pump will not respond to pump chain communication while it is in a setting mode
(entered when the user presses the SET key). The pump can still be controlled from
the keypad while it is in a pump chain. Control data that is changed via RS-232 will
NOT be stored in the pump’s non-volatile memory unless requested with the “SAV”
command or other data is changed from the keypad. Each command sent to the pump
chain is a string of ASCII characters, with leading zero’s on numbers and all spaces
optional. Numbers are a maximum of five digits. The following symbols are used in
describing the commands:
Symbol Meaning
[. . . ] optional
{. . . } select one
| either–or
f digits 0-9 or a decimal point
d digits 0-9
<cr> carriage return (ASCII 13)
<lf> line feed (ASCII 10)
<float> f f f f f f
<integer> d d d d d
<text> any string of ASCII characters
Command Formats Meaning
<cr> Stops all pumps. All pumps on the pump
chain interpret this as a stop command, but
do not respond with a prompt.
pump address, <cr> Request for prompt. The pump with the
indicated address responds with its prompt.
optional pump address, Sends a command to a pump. The pump
command, <cr> with the indicated address executes the
command then responds with its prompt.
The optional pump address, if not speci-
fied, will default to pump address 0.
After each command is received and executed, the pump acknowledges the command
with a prompt. Preceding the prompt will be the text response,if applicable. The text
response will be one or more lines of ASCII text, each preceded by a line feed and ter-
minated by a carriage return:
<lf>, <text>, <cr>
To Next Page
Loading...