HARVARD 33, MA1-55-3333 User Manual

Syringe Pump Model 33 MA1-55-3333

Model 33

Twin Syringe Pump

User's Manual

Publication 5390-001 Revision B

Publication 5390-001 Revision B

1

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

SUBJECT PAGE

Table of Contents

Table of Contents ..............................................................1

Warranty and Repair Information ....................................2

Specifications ....................................................................3

Features ..............................................................................4

Initial Setup ........................................................................5

Loading Syringes ..............................................................6

User Interface..................................................................7-8

Description of Keys ......................................................8

Entering Data......................................................................9

Operation ..........................................................................10

Diameters ....................................................................10

Pumping Rates............................................................10

Selecting the Run Mode..............................................10

Selecting the Pumping Directions ..............................10

Running the Pump ......................................................10

Single Syringe Operation ............................................10

Valve Control Box ............................................................11

Pinch Valve Connectors ............................................12-13

External Control and Interfaces ................................14-15

Attaching/Configuring a Pump Chain ..........................14

TTL Devices ................................................................15

Foot Switch Input ........................................................15

Pump Chain Commands ............................................16-20

Pump Commands and Responses ............................17

Pump Chain Error Messages ......................................20

Appendices..................................................................21-27

A Syringe Diameters in mm....................................21

B Nominal Min/Max Flow Rates ............................22

C Command Information ........................................23

D RS-232 Specifications ........................................24

E TTL Connector Specifications ............................24

F Pump to PC Connection ....................................25

G Maintenance........................................................26

H Troubleshooting ..................................................27

I Accessories ........................................................28

J Custom Applications............................................28

Publication 5390-001 Revision B

2

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

CAUTION: Not for clinical use on human patients.

Warranty and Repair Information

Serial Numbers

All inquires concerning our product should refer to the serial number of the unit.Serial
numbers are located on the rear of the chassis.

Calibrations

All electrical apparatus is calibrated at rated voltage and frequency.While the flow will
stay calibrated, the peak will vary.

Warranty

Harvard Apparatus warranties this instrument for a period of one year from date of pur­chase.At its option, Harvard Apparatus will repair or replace the unit if it is found to be
defective as to workmanship or material.

This warranty does not extend to damage resulting from misuse,neglect or abuse, normal
wear and tear, or accident.This warranty extends only to the original customer purchaser.

IN NO EVENT SHALL HARVARD APPARATUS BE LIABLE FOR INCIDENTAL OR
CONSEQUENTIAL DAMAGES. Some states do not allow exclusion or limitation of inci-

dental or consequential damages so the above limitation or exclusion may not apply to
you.THERE ARE NO IMPLIED WARRANTIES OF MERCHANTABILITY, OR FITNESS
FOR A PARTICULAR USE, OR OF ANY OTHER NATURE. Some states do not allow
this limitation on an implied warranty, so the above limitation may not apply to you.

If a defect arises within the two-year warranty period, promptly contact Harvard

Apparatus, Inc. 84 October Hill Road, Building 7, Holliston, Massachusetts
01746-1371 using our toll free number 1-800-272-2775, or outside the U.S. 508-893-

8999. Goods will not be accepted fir return unless an RMA (returned materials author­ization) number has been issued by our customer service department.The customer is
responsible for shipping charges. Please allow a reasonable period of time for comple­tion of repairs, replacement and return. If the unit is replaced, the replacement unit is
covered only for the remainder of the original warranty period dating from the pur­chase of the original device.

This warranty gives you specific rights, and you may also have other rights which vary
from state to state.

Repair Facilities and Parts

Harvard Apparatus stocks replacement and repair parts.When ordering, please describe
parts as completely as possible, preferably using our part numbers. If practical, enclose
a sample or drawing.We offer a complete reconditioning service.

CAUTION

This pump is not registered with the FDA and is not for clinical use on human patients.

Publication 5390-001 Revision B

3

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Specifications

Harvard Pump 33 Specifications

Accuracy ±0.35%

Reproducibility ±0.1%

Type Dual Syringe Infusion/Withdrawal Parallel/Reciprocal

Size, L x W x H (286 x 311 x 152 mm) 11.25 x 12.25 x 6 in

Weight (6.8 kg) 15 lbs

Power 115/230 VAC, 50-60 Hz via selector switch, 45 W

Fuse 1 A (115 V), 0.5 A (220 V)

Leakage to Ground Typically < 10 µA

Ground Resistance Typically < 0.06 Ω

Voltage Operating Range 95-130 VAC, 220-260 VAC

Drive Motors 2 motors, each 0.9 degree steppers

Motor Drive Circuitry Microprocessor controlled from 1/2 to 1/4 microstepping

Timing Belt Drive 2:1

Lead Screw Pitch 24 threads/inch

Motor Steps per One 1600 at 1/2 stepping or 3200 at 1/4 stepping
Revolution of Lead Screw

Step Rate:

Minimum 27.3 sec/step

Maximum 416.7 µsec/step

Pusher Advance per Step:

Minimum 0.330729 µm

Pusher Travel Rate:

Minimum 0.726699 µm /min

Maximum 95.25 mm/min

Dynamic Speed Range 131,072 to 1

Force 40 lbs max.

Pressure 99.5 PSI max. with 20 ml stainless steel syringe

Calibration Enter syringe diameter, any size, any make, up to 50 mm

diameter

Syringe Size 10 µl (min.), 50 ml (max.)

Flow Rate Range:

Minimum 0.0073 µl/hr (10 µl syringe)

Maximum 53.346 ml/min (50 ml syringe)

Display 5 digits plus 14 indicator LEDs

RS-232 Interface Chained dual bidirectional ports

Non-Volatile Memory Storage of all settings

Publication 5390-001 Revision B

4

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Features

Pressure and Speed

Pump 33 can deliver up to 53.346 ml/min with a 50 ml syringe,and is capable of pres­sures of up to 99.5 PSI with a 20 ml syringe.

Independent Syringe Diameters and Rates

In the Proportional Mode, separate syringe types and rates may be set.

Variable Syringes

Enter the inside diameter of the syringes being used.

Modes of Operation

Auto Stop

Both syringes will operate at same rate and stop when either syringe reaches a
limit stop.

Continuous Run

With both syringes operating at same rate,when end of travel is reached, the pump
automatically reverses the direction of travel for both syringes.The external valves,
optionally attached to the syringes, will be automatically activated or deactivated.

Proportional

Pump operates as in Auto Stop,but independent rates and diameters are set for each syringe.

Parallel/Reciprocal Operation

Syringes may pump in the same direction (parallel) or opposite directions (reciprocal).

External Connections

TTL

Allows pump operations to be synchronized with external devices or by a person
at a distance from the pump. Direction of pump travel can be set via a TTL pin.
Also,TTL pins are used to control an external valve for refilling and provide an out­put to indicate whether or not the pump is running. Additional TTL pins are avail­able for general use.

RS-232

Multiple pumps can be chained together and remotely controlled from a computer or
any device communicating via RS-232.

Valves

Models MA1-55-3334 and MA1-55-3335 include a valve assembly which allows auto­matic selection of infusion and refill lines.

Non-Volatile Memory

All operational data entered into the pump from the keypad or requested to be saved
via RS-232, will be stored. On power up, all ettings from when it was powered down
will be recalled and the display will blink until the pump receives its first command.

Stall Detection

An optical detector on each motor is used to verify expected movement of the motors.
If motor is prevented from turning due to jamming or kinking of the tubing,the pump
stops and the display indicates a stall condition by blinking the run light and the
syringe direction light of the stalled syringe. Pump 33 employs a microcontroller
which controls a small step angle stepping motor that drives a lead screw and half nut.
Microstepping techniques are used to further reduce the step angle making flow pul­sation negligible. A keypad is used for entry of operating data to the pump or data can
be entered via RS-232. The microcontroller calculates the cross-sectional area of the
syringe selected and calibrates the flow rate.

Publication 5390-001 Revision B

5

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Initial Setup

1. Read the manual.

2. Locate the voltage selector switch on the rear panel of the pump and set it to the

voltage being used. If other than 115VAC, 60 Hz is being used, the plug must be
cut off and an appropriate plug installed, observing the polarity of the interna­tional line cord used:

Brown – high
Blue – neutral
Green – ground

3. Turn on main power switch located directly above the line cord on the rear

panel.The display will illuminate indicating that the power connections are cor­rect.The flashing display indicates that power has just been applied.

4. Load syringes.

Publication 5390-001 Revision B

6

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

SYRINGE 1

SYRINGE 2

REFILL

LIMIT STOP

INFUSE

LIMIT STOP

LIMIT

SWITCHES

1

3

4

2

1. The syringe holder and pusher block are fitted with movable retaining brackets

which hold the syringe barrel and plunger when refilling.When loading the
syringe into the pump, it is necessary to adjust these brackets.The pusher block
is fitted with a mechanism to release the drive nut from the leadscrew.This
allows the block to move freely so the syringe to be loaded.

2. Loosen the screws on the syringe block and pusher block to free the retaining

brackets (2 and 3, Figure 1)

3. To free the pusher block from the leadscrew, turn the knob on the front of the

block (1) until the pin in the knob slips into the hole in the block.

4. The syringe clamp locking screw on the right side of the syringe block (4)

should be loosened and the clamp rotated to the side.

5. Place the syringe barrel on the syringe holder block and move the pusher block

to accommodate the plunger.

6. Make sure the syringe barrel flange and the plunger flange are held by the retain-

ing clamps. Press the retaining brackets firmly against the flanges and tighten the
retaining screws.

7. Rotate the syringe clamp and press down firmly on the syringe barrel. Secure in

place by tightening the locking screw (4).

Setting Limit Stops

To set the limit stops, loosen thumbscrews on limit stops and slide stops to desired
travel limits (infuse limit & refill), tighten thumbscrews.

Loading Syringes

Figure 1. Syringe Loading

Publication 5390-001 Revision B

7

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

User Interface

Auto Stop

Proportional

Continuous

Remote

Run

ml/min

µl/min

ml/hr

µl/hr

mm

Syringe 1

Syringe 2

The user interface consists of a display area and a keypad. The display consists of a 5
digit LED display and 14 LED indicators. The display will be showing either the default
display or an informational message. The two syringes are referred to as Syringe 1 and
Syringe 2. Syringe 1 is located towards the front and Syringe 2 is located towards the
rear. Rate 1 refers to the set flow rate of Syringe 1 and Rate 2 refers to Syringe 2.

By default, the display will be showing Rate 1. Informational messages are shown
when the user queries another data value by pressing the corresponding key, or when
the pump is alerting the user to a problem. Such problems are a value out of range
(oor) or the pump stalling (StALL).

The 14 LED indicators are divided into three sections: Pump mode and state, syringe
directions, and units of value being displayed. See Figure 2.The LED indicators are
as follows:

Pumping Mode and State LEDs

Meaning

Auto Stop Pump is in Auto Stop mode
Proportional Pump is in Proportional mode
Continuous Pump is in Continuous mode
Remote Pump Chain communication
Run At least one motor is operating

Syringe Directions LEDs

Comprising of 4 indicators, these LED’s indicate the direction of the syringes when
illuminated. When blinking, indicates the corresponding motor is stalled, or data per­taining to that syringe is being entered.

Unit LEDs

Meaning

ml/mn milliliters per minute
µl/mn microliters per minute
ml/hr milliliters per hour
µl/hr microliters per hour
mm millimeters

Figure 2. User Interface

Publication 5390-001 Revision B

8

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

User Interface: Description of Keys

Set

Rate

1

1

7

2

8

3

9

4

0

5

.

6

Enter

HARVARD

‘33’ Syringe Pump

Data Entry

Diameter

1

Rate

2

Diameter

2

Stop

Run

Change

Direction

Parallel

Reciprocal

Select

Mode

Proportional Only

Set Keys

Toggle

The keypad consists of 21 keys used for entering control information and data into the
pump. These keys are grouped into 3 sections (see Figure 3 above): Set keys, toggle

keys, and data entry keys.

Set Keys

Set Allows modification of a data item in this group of keys.To

modify a data item, press the relevant key after pressing the
SET key.

Rate 1 Displays/sets current rate of syringe 1. Also syringe 2 rate if

current mode is not Proportional. Scrolls through rate units
when setting.

Rate 2 Displays/sets current rate of syringe 2. Scrolls through rate

units when setting. Key only valid in Proportional mode.

Diameter 1 Displays/sets current diameter of syringe 1. Also diameter of

syringe 2 if current mode is not Proportional.

Diameter 2 Displays/sets current diameter of syringe 2. Key valid in

Proportional mode.

“1” Used to display and set current Pump Chain address and to

scroll through supported baud rates while setting.

Toggle Keys

Parallel/ Chooses between Parallel and Reciprocal pumping operation.
Reciprocal

Select Mode Chooses between Proportional, Continuous Run, or Auto Stop.

LED indicators display current mode. Pump must be stopped
to change modes.

Change Reverses direction of both syringes and sets the valve control
Direction output as appropriate.

Run/Stop Starts or stops the pump.

Data Entry Keys

1 through 0, . Used to facilitate the entering of numeric data values.

Enter Stores displayed data value when entering data.

Figure 3. Keypad Interface

Publication 5390-001 Revision B

9

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Entering Data

Set Keys

The keys in this group are used to modify or review settings of the pumps control
data. To review the current setting of a control data item,simply hold down the rele­vant key and the data setting will appear in the display.

To modify a data setting, first press then release the green SET key. The display will
then read “SET”. Press the key in the SET key group of the data item that is to be mod­ified. The display will show the current setting. Data is entered into the pump by
either entering a numerical value or, in the case of entering a baud rate, by scrolling
through a menu of choices. Always press ENTER to terminate each data request by the
pump.

When entering a numerical value, the LEDs corresponding to the data being entered
will blink. Using the yellow data entry keys on the right side of the keypad (see Figure

3) enter the new data value. Up to five digit numbers are accepted for rates and diam­eters, including up to four decimal places. Entering more than five digits will clear the
previous five digits in the display. Press the green ENTER key when the desired data
value is displayed.

If the data value entered is outside the pump’s operating parameters, the display will
read “oor” meaning “Out of Range”. Pressing any key will restore the display with the
original data value. Enter another data value within the pump’s parameters or just
press ENTER to reuse the original data value.

The data value entered can be reviewed as described above. Note:Certain data items
have multiple settings. For these, after the ENTER key is pressed, the display will
prompt you for the additional information. Various rules apply to when,what and how
data can be set at various times. See the relevant section for further details.

Toggle Keys

The keys in this group, when pressed successively, select different states. Each state
change is accompanied by a corresponding change in status LED display.

To operate, Pump 33 needs to know the diameter(s) of the syringes, the rate(s) of
pumping, pumping directions, and the mode of operation. Except for Proportional
mode, syringe 2 is assumed to be the same diameter as syringe 1 and will pump at
same rate as syringe 1.

Publication 5390-001 Revision B

10

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Operation

Diameters

The pump must be stopped when entering a diameter. Diameter 1 is the diameter of
both syringes, except in Proportional mode. In Proportional mode, enter the diameter
of each syringe separately; Diameter 1 for syringe 1 and Diameter 2 for syringe 2.When
entering a diameter, the 2 direction LEDs corresponding to the syringe and the “mm”
LED will blink. Enter the inside diameter of the syringe in millimeters. After a new
diameter is entered the corresponding rate is set to 0. This is done for reasons of safe­ty. The maximum diameter is 50 mm. See Appendix A for a list of syringe diameters.

Pumping Rates

Rate 1 is the rate of pumping of both syringes, except in Proportional mode. In
Proportional mode, enter the rate of each syringe separately, Rate 1 for syringe 1 and
Rate 2 for syringe 2.When entering a rate, the directional LEDs corresponding to the
syringe and the current units LED will blink. Use the corresponding rate key (RATE 1
or RATE 2) to scroll through the rate units: ml/mn, ml/hr, µl/mn and µl/hr. The mini­mum and maximum rates permitted vary depending on the diameter of the syringe. If
an “OOR” message, meaning “Out of Range” is displayed when entering a rate, try using
a different syringe for your application.

Selecting the Run Mode

To select the run mode, press the SELECT MODE key to advance the run mode LED
indicator. Advance the run mode indicator to the desired mode, either Auto Stop,
Proportional, or Continuous mode.

Auto Stop Both syringes pump according to DIAMETER 1 and RATE 1

until syringe 1 reaches the limit switch when pump will stop.

Proportional Each syringe pumps independently;syringe 1 according to

DIAMETER 1 and RATE 1,syringe 2 according to DIAMETER 2
and RATE 2. When syringe 1 reaches limit switch, pump stops.

Continuous Both syringes pump according to DIAMETER 1 and RATE 1.

When syringe 1 reaches limit switch, the direction of pump­ing for both syringes is reversed and pumping continues.
The valves, if applicable, are set accordingly.

Selecting the Pumping Directions

Parallel or Reci- Pressing the PARALLEL/ RECIPROCAL key reverses
procal Operation pumping direction of syringe 2.

Change Direction Pressing the CHANGE DIRECTION key reverses the pump-

ing directions of both syringes. When valves are used in the
system then the valve(s) setting(s) will be changed simulta­neously with the change in direction.

Running the Pump

Pressing RUN/STOP key starts pump and illuminates Run LED on display. Pressing
RUN/STOP key again stops pump. While running, a new rate can be set. The new rate,
for relevant syringe(s), takes effect when ENTER key is pressed. Pump will operate
according to selected run mode. Pump can also be started and stopped via external
controls. If operation of one of the motors is impeded, both motors will stop and dis­play will read “StALL”, with the “run”LED and the direction LED of stalled syringe blink­ing. Investigate cause of stalling and then press RUN/STOP key to resume pumping.

Single Syringe Operation

To operate only one syringe, select the Proportional mode and set the rate of the
syringe not in use to 0.

Publication 5390-001 Revision B

11

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Valve Control Box

Applicable to Following Models

Model No. Description

MA1-55-3334 Supplied with 1/8" ID, 1/4" OD silastic tubing and connector to syringe

MA1-55-3335 Supplied with 1/4" OD 304 stainless steel tubing with Swagelok fittings

Setting up Valve

Set up consists of:

1. Pump to Valve Electrical Connections:

The cable fitted with a male 3 pin connector must be connected to the
female connector on the rear of the Model 33. The Model 33 should be
turned off when making/breaking this connection.

2. Valve tubing to syringe hook up:

The valve(s) are de-energized when the front mechanism (#1) is running in
the INFUSE direction. The syringe on the #1 mechanism when infusing
should therefore be connected to the lower tubing in the pinch valve (see fig­ures on next page).

Publication 5390-001 Revision B

12

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Pinch Valve Connectors

Valve Shown de-energized

Top Tube

Bottom Tube

Top

Bottom

Top

Bottom

Top

Bottom

Top

Bottom

Rear

Front

Fill

Output

Top

Bottom

Top

Bottom

Top

Bottom

Top

Bottom

Rear

Front

Fill

Rear

Output

Front

Fill

Front

Output

Rear

Figure 4. Pinch Valve Connections

Figure 5. Continuous Delivery. Pump in Reciprocal Mode.

Figure 6. Dual Delivery followed by Refill. Pump in Parallel Mode.

Publication 5390-001 Revision B

13

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Stainless Steel Valve Connectors

Swage lock fittings should be finger tight plus 1-1/4 turns. Tubing is 304, stainless 1/4"
OD, wall thickness 0.035"

P = Com.
B = Normally Open
A = Normally Closed

A

Rear

Front

A

P

P

B

B

Fill

Output

Figure 7. Continuous Delivery. Pump in Reciprocal Mode.

A

Rear

Front

A

P

P

B

B

Output

Front

Output

Rear

Fill

Front

Fill

Rear

Figure 8. Dual Delivery followed by Refill. Pump in Parallel Mode.

Publication 5390-001 Revision B

14

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

External Control and Interfaces

VOLTAGE

SELECT

RS-232

OUT IN

I/O

TTL

PORT #2

PORT #1

Figure 9. External Interface

External devices that can be attached to the Pump 33 include external valves, pump
chain, and TTL devices. See the appropriate appendixes for specification details on
attaching devices.

Attaching a Pump Chain

On the back of the pump are two telephone jack type connectors. These are the RS­232 ports. Looking at the back of the pump,the connector on the right is port 1 and
the left is port 2. Attach the RS-232 connectors in the appropriate port according to
the following chart:

Device Port Number

Computer 1
Pump Chain 2

Configuring the Pump Chain

After pressing SET and 1, the Remote LED will blink, indicating the pump is request­ing its pump chain configuration:

1. First, the display will show “Adr:nn”, with the colon blinking, where “nn” is the
current pump chain address. Enter the 2 digit address assigned to the pump
and press ENTER. Note: Each pump in the chain needs a unique address.

2. Next, the display will show “b:nnnn”, with the colon blinking, where “nnnn” is
the current baud rate. Use the 1 key to select between the supported baud
rates: 300, 1200,2400 and 9600; then press ENTER. Note: Each pump in the
chain must have the same baud rate.

See the section on Pump Chain Commands for pump chain control information.

Publication 5390-001 Revision B

15

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

External Control and Interfaces

Attaching a Valve Control Accessory Box

Attach the valve control cable to the pump’s accessory valve connection (see Figure

9). Refer to the Valve Control Box section.

TTL Devices

The pump does not need to be configured to attach a TTL device. To attach a TTL
device, simply plug the appropriate TTL connector into the 9 pin connector on the
rear of the pump. See Appendix E for wiring specifications.

Foot Switch Input

Used to start and stop the pump. Pressing the foot switch performs the same function
as pressing the RUN/STOP key on the keypad. The foot switch connector allows
remote or automated operation of the pump.

Timer Input

Opening the timer input starts the pump. Closing the timer input stops the pump.
The timer input allows for an externally controlled pumping interval.

Pumping Direction Input

Sets the direction of pumping. Opening the directional input sets syringe 1 to
infuse. Closing the input sets syringe 1 to refill. The pumping direction input is
not recognized when data is being entered from the keypad. Syringe 2 changes
direction appropriately. Also, the valve control output is set appropriately.

Directional Indicator Output

The Directional Indicator output is an indicator of the direction of pump travel. When
the output is a logical high, syringe 1 is set to infuse. A logical low indicates refill. A
valve attached to this output enables automatic selecting of infuse and refill vessels.

Running Indicator Output

Provides a signal to another device indicating whether or not the pump is running.

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 ter­minated by a carriage return:

<lf>, <text>, <cr>

Publication 5390-001 Revision B

17

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Pump Chain Commands

A prompt is a string of ASCII characters sent by a pump,indicating the pump’s address
and its present state:

<lf>, 1 or 2 digit address, prompt character

Prompt Characters Meaning

: Pump stopped
> Syringe 1 infusing
< Syringe 1 refilling
* Pump stalled

Pump Commands and Responses

RUN

Starts pumping according to the present setting of the pump. If pump already pump­ing, a “Not Applicable” error is returned.

STP

Stops pump if it was running. If pump already stopped, a “Not Applicable”error is returned.

RAT [{A|B}] [[<float> [<units>]]

Request to set or query infusion rate settings.

Set syringe 1 rate:

RAT rate
RAT rate units
RAT A rate
RAT A rate units

Set syringe 2 rate (only valid in proportional mode):

RAT B rate
RAT B rate units

Rate is of the format: f f f f f f

Units are one of Meaning

UM µl/mn
UH µl/hr
MM ml/mn
MH ml/hr

Rate 2 is only accepted when mode is Proportional. If rate is accepted and valid, rate
will become the new rate. If the rate is invalid, an “Out Of Range” error is returned.

Query syringe 1 rate:

RAT
RAT A

Query syringe 2 rate (only valid in proportional mode):

RAT B

Response is of the following format:

f f f f f f <units>

Where units are one of the following:

ml/mn, ml/hr, µl/mn, µl/hr

Publication 5390-001 Revision B

18

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Pump Chain Commands

DIA [{A|B}] [<float>]

Request to set or query syringe diameter settings.

Set syringe 1 diameter:

DIA diameter
DIA A diameter

Set syringe 2 diameter (only valid in proportional mode):

DIA B diameter

Corresponding syringe’s rate will be zeroed.

Diameter is of the format:

f f f f f f

Units are millimeters.

Diameter 2 is only accepted when mode is proportional. If diameter is accepted and
valid, diameter will become the new diameter. Diameter will not

be accepted if the
pump is running and a “Not Applicable”error is returned. If the diameter is invalid,an
“Out Of Range” error is returned.

Query syringe 1 diameter:

DIA
DIA A

Query syringe 2 diameter (only valid in proportional mode)

DIA B

Response is of the following format:

f f f f f f

Units are millimeters.

MOD [{AUT|PRO|CON}]

Request to set or query pumping mode

SET: Command Meaning

MOD AUT Puts pump in Auto Stop mode
MOD PRO Puts pump in Proportional mode
MOD CON Puts pump in Continuous mode

If pump is running,command will not be accepted and a “Not Applicable”error is returned.

Query:

MOD

Possible Responses Meaning

AUTAuto Stop mode
PRO Proportional mode
CON Continuous mode

DIR [{INF|REF|REV}]

Request to set or query pumping direction of syringe 1.

SET: Command Meaning

DIR INF Sets syringe 1 pumping direction to infusion
DIR REF Sets syringe 1 pumping direction to refill
DIR REV Reverses pumping direction of syringe 1

Direction of syringe 2 is set appropriately.

Publication 5390-001 Revision B

19

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Pump Chain Commands

Query pumping direction of syringe 1:

DIR

Response will be one of:

INFUSE
REFILL

PAR [{ON|OFF}]

Request to set or query Parallel or Reciprocal setting.

SET: Command

Meaning

PAR ON Sets syringes to parallel pumping direction.
PAR OFF Sets syringes to reciprocal pumping direction.

Direction of syringe 2 changes appropriately,while direction of syringe 1 does not change.

Query:

PAR

Possible Responses Meaning

ON Parallel
OFF Reciprocal

IN <d>

Request to read in the TTL logic level at the specified pin,“d”, on the external 9 pin
D-SUB connector.

Valid pin numbers for input are:

6, 7 and 8

Possible Responses Meaning

ON TTL level high
OFF TTL level low

If the pin specified is invalid, a “Not Applicable” error is returned.

OUT <d> = {ON|OFF}

Request to set the TTL logic level at the specified pin “d”on the external 9 pin D-SUB connector.

ON – Set pin to a logic high
OFF – Set pin to a logic low

Valid pin numbers for output are:

4 and 5

If the pin specified is invalid, a “Not Applicable” error is returned.

SAV

Request to save pump settings in the pumps non-volatile memory (NOVRAM).
Normally, settings changed from a pump chain are not stored in the pump’s NOVRAM
and are lost after power down.

VER

Request for version of pumps embedded software.
Response for the present version will be: 33V2.0

Publication 5390-001 Revision B

20

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Pump Chain Commands

Pump Chain Error Messages

Error messages are in the format:

<lf>, <message>,<cr>,

and are followed by a prompt. <Message> is one of the following:

Possible Responses Meaning

? Syntax error in a received command

NA Command “Not Applicable” at this time.

OOR “Out Of Range”. Control data is out of

pump's operating range.

Publication 5390-001 Revision B

21

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix A: Syringe Diameters in mm

Te r umo

Size Diameter

3 cc 8.95 mm

5 13.00
10 15.80
20 20.15
30 23.10
60 29.10

––––––––––––––––––––––

Sherwood–Monoject

Plastic

Size Diameter

1 cc 4.65 mm

3 8.94

6 12.70
12 15.90
20 20.40
35 23.80
60 26.60

140 38.40

––––––––––––––––––––––

Popper & Sons, Inc.

‘Perfektum’ Glass

Size Diameter

0.25 cc 3.45 mm

0.5 3.45

1 4.50

2 8.92

3 8.99

511.70
10 14.70
20 19.58
30 22.70
50 29.00

100 35.70

––––––––––––––––––––––

Renfac

Size Diameter

2 cc 9.12 mm

5 12.34
10 14.55
20 19.86
30 23.20
50 27.60

SGE Scientific

Glass Engineering

Size Diameter

25 µl 0.73 mm

50 1.03
100 1.46
250 2.30
500 3.26

1.0 ml 4.61 mm

2.5 7.28
5 10.30

10 14.57

––––––––––––––––––––––

Hamilton–Microliter

Series Gastight

Size Diameter

0.5 µl 0.103 mm
1 0.1457
2 0.206

5 0.3257
10 0.460
25 0.729
50 1.031

100 1.46
250 2.3
500 3.26

1.0 ml 4.61 mm

2.5 7.28

5 10.3
10 14.57
25 23.0
50 32.6

––––––––––––––––––––––

Becton Dickinson

Glass-All Types

Size Diameter

0.5 µl 4.64 mm

1 4.64

2.5 8.66

5 11.86
10 14.34
20 19.13
30 22.70
50 28.60

100 34.90

Harvard

Stainless Steel

Size Diameter

8 cc 9.525 mm

20 19.130

50 28.600
100 34.900
200 44.755

––––––––––––––––––––––

Becton Dickinson

Plastic ‘Plasti-

pak’

Size Diameter

1 cc 4.78 mm

3 8.66

5 12.06
10 14.50
20 19.13
30 21.70

50/60 26.70

––––––––––––––––––––––

Air–Tite

‘All Plastic’

Size Diameter

2.5 cc 9.60 mm

5 12.45
10 15.90
20 20.05
30 22.50
50 29.00

––––––––––––––––––––––

Unimetrics

Series 4000 &

5000

Size

Diameter

10 µl 0.460 mm

25 0.729
50 1.031

100 1.460
250 2.300
500 3.260

1000 4.610

Publication 5390-001 Revision B

22

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix B: Nominal Min/Max Flow Rates

Minimum flow rates are taken from the smallest inside diameters and maximum flow
rates are taken from the largest inside diameters of the syringes supplied by the eleven
most widely used syringe manufacturers.

Nominal Minimum/Maximum Flow Rates for Various Syringes
(Actual Limits will vary depending on manufacturer)

Syringe µl/hr µl/min ml/hr ml/min

Size Min. Max. Min. Max. Min. Max. Min. Max.

10 µl 0.0073 950.05

25 µl 0.0183 2386.10

50 µl 0.0365 4772.50

100 µl 0.0731 9570.50

250 µl 0.1813 23.751

1000 µl 0.7281 95.418

1 ml 0.7828 102.580

2 ml 2.8493 373.430

2.5 ml 1.8156 237.950

3 ml 2.5691 336.710

5 ml 4.9824 653.010

10 ml 7.2024 15.733

20 ml 12.5360 27.384

30 ml 16.1310 35.236

50 ml 24.4201 53.346

Publication 5390-001 Revision B

23

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix C: Command Information

Pump Chain Command Summary

All spaces in command are ignored. Maximum 5 digits per integer, or float data.

command = > [<adr>] [<cmd>] <CR>

adr = > [d]d 1 or 2 digit address

cmd => RUN Start pump

STP Stop pump
RAT [A] [<float> [<units> ] ] Set/query syringe 1 rate
RAT B [<float> [<units> ] ] Set/query syringe 2 rate
DIA [A] [<float>] Set/query syringe diameter 1
DIA B [<float>] Set/query syringe diameter 2
MOD [{AUT|PRO|CON}] Set/query pumping mode
DIR [{INF|REF|REV}] Set/query pumping direction
PAR [{ON|OFF}] Set/query Parallel/Reciprocal
IN <d> Read TTL pin d
OUT <d> = {ON|OFF} Set TTL pin d
SAV Save settings in NOVRAM
VER Query software version

units = > {UM|UH|MM|MH} µl/mn, µl/hr, ml/mn, ml/hr

Command Response Output Format:

output = > [<response>] <prompt>
response = > <response> <response>

<lf> <message> <cr>

prompt = > <lf> <adr> : Stopped

<lf> <adr> > Syringe 1 infusing
<lf> <adr> < Syringe 1 withdrawing

<lf> <adr> * Pump stalled
adr = > [d]d 1 or 2 digit pump address
message = > ? Unrecognized command

NA Command not presently applicable

OOR Entered value out of range

<text>

<integer>

<float>

All spaces ignored. Maximum 5 digits per integer or floating point number.

Legend

float = > f f f f f f
f= >d|.
integer = > d d d d d
d= >0|1|2|3|4|5|6|7|8|9
b= >space
cr = > (ASCII 13)
lf = > (ASCII 10)
text = > (any string of ASCII characters)
< . . .> non-terminal
upper case terminals
[ . . .] optional
{ . . .} select one
| either-or

Publication 5390-001 Revision B

24

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix D: RS-232 Specifications

Pump Chain

Pump Port 1: Computer

control side

Pump Port 2: Connection for

remainder of
pump chain

Baud Rate: 300, 1200, 2400

or 9600
Word Size: 8
Parity: none
Stop Bits: 2

TTL Connections are via a 9 pin D-sub type connector.All inputs are internally pulled
up to a logic high. All user definable pins are controlled via the IN and OUT pump
chain commands. See Pump Chain Commands.

Pin Assignments

1. Vss (Ground reference,

logic low)

2. Directional Indicator:

Low – Syring 1 Infusing
High – Syringe 1 Refilling

3. Pump Running Indicator

Low - Pumped Stopped
High - Pump Running

4. User Definable Output

5. User Definable Output

6. Foot Switch Input

Falling edge starts/stops pump

7. Timer Input

Rising edge starts pump
Falling edge stops pump

8. Directional control input

Rising edge sets Syringe 1 to infuse
Falling edge sets Syringe 1 to refill

9. Vcc (Logic High Reference)

Figure 10.TTL Connector Specifications

Figure 9. RS-232 Specifications

Appendix E: TTL Connector Specs

1 2 3 4 5

6 7 8 9

Directional Indicator

Running Indicator

User Definable Outputs

Foot Switch

Timer

Refill

Vcc (5V)

Tr ansmit

Receive

GND
GND

GND
GND
Tr ansmit
Receive

Port #2

(out)

Port #1

(in)

Logic Low: 0 V – 0.5 V

Max. 2 mA current sink

Logic High: 2 V – 5 V

Max. 400 mA current source

Publication 5390-001 Revision B

25

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix F: Pump to PC Connection

3

RJ11/RJ12

6

RJ12

- 6 x 6

22/2000

5

4/

Front View

4400

“Pump”

Publication 5390-001 Revision B

26

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix G: Maintenance

Pump 33 requires no special maintenance other than keeping it clean by avoiding acci­dental spills of pumped material.

The two guide rods and the lead screw should be sparingly lubricated periodically
with the Magnalube-G R grease provided with the pump. This Teflon R based grease
is available either from Harvard Apparatus or Carleton-Stuart Corp. 13-02 44th Ave.,
Long Island City, NY 11101.

Solvents of any type should never be used to clean the pump. A mild detergent solu­tion may be used to clean the keypad.

Fuse Replacement

Make sure power cord is disconnected from main supply before replacing fuse.
Remove bottom cover on pump by removing four (4) rubber feet and four (4) screws.
Locate fuse on power supply module. Remove fuse from fuse clip. Use caution no to
break fuse when removing. Replace fuse, bottom cover, screws and rubber feet. For
continued fire protection replace fuse only with 250V fuse of the specified type and
rating. (3AG 1AMP 250V SLO-BLO)

1 AMP S.B.

FUSE

Figure 11. Fuse Replacement

WARNING:
Use in manner not specified by manufacturer
may impair protection provided by equipment.

Publication 5390-001 Revision B

27

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix H: Troubleshooting

RS-232 Difficulties

Verify that the baud rates and data framing parameters on all devices are the same.
With a pump chain,a “Communication timeout”error on a computer is usually caused
by the computer errantly handshaking on the RTS, CS and/or DSR lines. Verify pins 4,
5 and 6, on the 25 pin connector, are jumpered on the computer side of the cable.

Display Messages:

All digits flashing

Pump has not received any commands since being powered on.

StALL

Also a syringe LED and Run LED flashing. This indicates that the pusher block travel
of the syringe corresponding to the syringe LED blinking has been impeded. This may
be caused by the syringe plunger hitting bottom, a kink in the tubing, syringe plunger
binding or any situation requiring more force to the head of the syringe than the pump
is capable of delivering. To restart the pump, remove the cause of stalling and press
RUN. The pump will continue the interrupted procedure where it stopped. Also note,
a large increase in the pumping rate while running could also stall the motor.

oor

Out of range. A value was entered or encountered in a pump program that was beyond
the pumps limits. Try using a different size syringe. Note that rates must be less than

42950. Express larger rates using different units.

- - - - -

Key pressed is not applicable.

Publication 5390-001 Revision B

28

Harvard Apparatus Model 33 Twin Syringe Pump User's Manual

Appendix I: Accessories

Appendix J: Custom Applications

Catalog No. Product

MA1-55-4144 Foot Switch

MA1-55-7760 Pump Chain Cable for connecting two or more pumps

MA1-55-4145 RS-232 Connector Cable for IBM and compatible personal computers

MA1-55-4146 RS-232 Connector Cable for other than IBM and compatible

personal computers

The Harvard 33 Syringe Pump lends itself to a multitude of OEM industrial applica­tions, for all types of custom pumping or pilot plant applications. Please contact the
Harvard Development Group if we can be of help.