Statement of Intended Use – The M300 for ISM transmitter is a single or dual- channel online
process instrument for measuring various properties of fluids. These include Conductivity*,
Dissolved Oxygen and pH/ORP. It will interface with ISM (Intelligent Sensor Management)
sensors from Mettler-Toledo, which connect to the transmitter using cables of varied lengths.
The transmitter features the Plug and Measure functionally. That means the calibration and
configuration data of each ISM sensor are stored in the sensor head and will be uploaded to the
transmitter after connection.
* Q4/2008
A large four line backlit Liquid Crystal Display conveys measuring data and setup information.
The menu structure allows the operator to modify all operational parameters by using keys on
the front panel. A menu-lockout feature, with password protection, is available to prevent the
unauthorized use of the meter. The M300 Multiparameter transmitter can be configured to use
its four analog and/or six relay outputs for process control.
The M300 Multiparameter transmitter is equipped with a USB communication interface. This
interface provides real-time data output and complete instrument configuration capabilities for
central monitoring via Personal Computer (PC).
2 Safety instructions
This manual includes safety information with the following designations and formats.
2.1 Definition of equipment and documentation symbols and
designations
WARNING: POTENTIAL FOR PERSONAL INJURY.
CAUTION: possible instrument damage or malfunction.
NOTE: Important operating information.
C
On the transmitter or in this manual text indicates: Caution and/or other possible hazard
including risk of electric shock (refer to accompanying documents)
The following is a list of general safety instructions and warnings. Failure to adhere to these
instructions can result in damage to the equipment and/or personal injury to the operator.
– The M300 Transmitter should be installed and operated only by personnel familiar with
the transmitter and who are qualified for such work.
– The M300 Transmitter must only be operated under the specified operating conditions
(see section 16).
– Repair of the M300 Transmitter must be performed by authorized, trained personnel only.
– With the exception of routine maintenance, cleaning procedures or fuse replacement, as
described in this manual, the M300 Transmitter must not be tampered with or altered in
– Mettler-Toledo accepts no responsibility for damage caused by unauthorized modifications
to the transmitter.
– Follow all warnings, cautions, and instructions indicated on and supplied with this product.
– Install equipment as specified in this instruction manual. Follow appropriate local and
national codes.
– Protective covers must be in place at all times during normal operation.
– If this equipment is used in a manner not specified by the manufacturer, the protection
provided by it against hazards may be impaired.
WARNINGS:
Installation of cable connections and servicing of this product require access to shock hazard
voltage levels.
Main power and relay contacts wired to separate power source must be disconnected before
servicing.
Switch or circuit breaker shall be in close proximity to the equipment and within easy reach of
the OPERATOR; it shall be marked as the disconnecting device for the equipment.
Main power must employ a switch or circuit breaker as the disconnecting device for the
equipment.
Electrical installation must be in accordance with the National Electrical Code and/or any other
applicable national or local codes.
NOTE: RELAY CONTROL ACTION: the M300 transmitter relays will always de-energize on loss of
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power, equivalent to normal state, regardless of relay state setting for powered operation.
Configure any control system using these relays with fail-safe logic accordingly.
NOTE: PROCESS UPSETS: Because process and safety conditions may depend on consistent
C
operation of this transmitter, provide appropriate means to maintain operation during sensor
cleaning, replacement or sensor or instrument calibration.
2.2 Correct disposal of the unit
When the transmitter is finally removed from service, observe all local environmental regulations
for proper disposal.
M300 models are available in both a 1/4DIN and 1/2DIN case size. The 1/4DIN is a panelmount only design and the 1/2DIN models provide an integral IP65 housing for wall-, or pipemount.
3.1 Overview 1/4DIN
1 – Hard Polycarbonate case 5 – USB Interface Port
2 – Five Tactile-Feedback Navigation Keys 6 – Relay Output Terminals
3 – Four-line LCD Display 7 – Analog Output/Digital Input Terminals
4 – Power Supply Terminals 8 – Sensor Input Terminals
3.2 Overview 1/2DIN
1 – Hard Polycarbonate case 5 – USB Interface Port
2 – Five Tactile-Feedback Navigation Keys 6 – Relay Output Terminals
3 – Four-line LCD Display 7 – Analog Output/Digital Input Terminals
4 – Power Supply Terminals 8 – Sensor Input Terminals
Enter the desired main Menu branch with the or keys. Use the and keys to
navigate through the selected Menu branch.
move the cursor under the UP Arrow character at the bottom right of the display screen and
press [Enter].
Transmitter Multiparameter M300 ISM 11
3.3.2.2 Escape
Press the and key simultaneously (escape) to return to the Measurement mode.
3.3.2.3 Enter
Use the ↵ key to confirm action or selections.
3.3.2.4 Menu
Press the key to access the main Menu.
3.3.2.5 Calibration mode
Press the key to enter Calibration Mode.
3.3.2.6 Info mode
Press the key to enter Info Mode
3.3.3 Navigation of data entry fields
Use the key to navigate forward or the key to navigate backwards within the changeable
data entry fields of the display.
3.3.4 Entry of data values, selection of data entry options
Use the key to increase or the key to decrease a digit. Use the same keys to navigate
within a selection of values or options of a data entry field.
NOTE: Some screens require configuring multiple values via the same data field (ex: configuring
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multiple setpoints). Be sure to use the or key to return to the primary field and the or
key to toggle between all configuration options before entering to the next display screen.
3.3.5 Navigation with ↑ in Display
If a ↑ is displayed on the bottom right hand corner of the display, you can use the or the
key to navigate to it. If you click [ENTER] you will navigate backwards through the menu
(go back one screen). This can be a very useful option to move back up the menu tree without
having to exit into the measuring mode and re-enter the menu.
Three options are possible for the “Save changes” dialog: Yes & Exit (Save changes and exit to
measuring mode), “Yes & ↑” (Save changes and go back one screen) and “No & Exit” (Don’t
save changes and exit to measuring mode). The “Yes & ↑” option is very useful if you want to
continue configuring without having to re-enter the menu.
3.3.7 Security Passwords
The M300 transmitter allows a security lock-out of various menus. If the security lock-out
feature of the transmitter has been enabled, a security password must be entered to allow
access to the menu. See section 9.3 for more information.
3.4 Display
NOTE: In the event of an alarm or other error condition the M300 Transmitter will display a
C
flashing in the upper right corner of the display. This symbol will remain until the condition
that caused it has been cleared.
NOTE: During calibrations, clean, Digital In with Analog Output/Relay/USB in Hold state,
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a flashing H will appear in the upper left corner of the display. This symbol will remain for
20 seconds until after the calibration or clean is completed. This symbol will also disappear
when Digital In is deactivated.
Inspect the shipping container. If it is damaged, contact the shipper immediately for instructions.
Do not discard the box.
If there is no apparent damage, unpack the container. Be sure all items shown on the packing
list are present.
If items are missing, notify Mettler-Toledo immediately
4.1.1 Panel cutout dimensional information – 1/4DIN models
1/4DIN Model transmitters are designed for panel-mount installation only. Each transmitter is
supplied with mounting hardware to provide fast and simple installation to a flat panel or flat
enclosure door. To insure a good seal and maintain NEMA/IP integrity of installation, the panel
or door must be flat and have a smooth finish. Hardware consists of:
Two – Snap-on Mounting brackets
One – Mounting gasket seal
Transmitter dimensions and mounting are shown in the figures below.
– Make cutout in panel (see dimensions cutout drawing).
– Be sure surface surrounding cutout is clean, smooth and free of burrs.
– Slide face gasket (supplied with transmitter) around transmitter from the back of the unit.
– Place transmitter into cutout hole. Be sure there are no gaps between the transmitter
and panel surface.
– Place the two mounting brackets on either side of the transmitter as shown
– While holding transmitter firmly into the cutout hole, push the mounting brackets
toward the backside of panel
– Once secure, use a screwdriver to tighten the brackets against the panel
– Face gasket will compress between transmitter and panel
4.1.3 Panel cutout dimensional information – 1/2DIN models
1/2DIN Model transmitters are designed with an integral rear cover for stand-alone wall mount
installation.
The unit may also be wall mounted using the integral rear cover. See installation instructions in
Section 4.1.4.
Below are cut-out dimensions required by the 1/2DIN models when mounted within a flat panel
or on a flat enclosure door. This surface must be flat and smooth. Textured or rough surfaces are
not recommended and may limit the effectiveness of the gasket seal provided.
Optional hardware accessories are available that allow for panel- or pipe-mount.
Refer to Section 15 for ordering information.
For Wall Mount:
– Remove rear cover from front housing.
– Start by unscrewing the four screws located on the face of the transmitter, in each corner.
This allows the front cover to swing away from the rear housing.
– Remove the hinge-pin by squeezing the pin from each end.
This allows the front housing to be removed from the rear housing
– Drill out wall-mount breakthroughs in the rear housing.
– Mount rear housing to wall using appropriate mounting hardware for wall surface. Be sure
it is level and securely fastened and the installation adheres to any and all clearance
dimensions required for transmitter service and maintenance.
– Insert two black protective covers (supplied with the M300 transmitter) over the fixing
hardware and into the space on the inside back cover, as shown in the drawing below.
This is necessary to maintain unit integrity.
– Replace the front housing to the rear housing. The unit is ready to be wired.
For Pipe Mount:
– Use only manufacturer-supplied components for pipe-mounting the M300 transmitter and
install per the supplied instructions. See section 15 for ordering information.
All connections to the transmitter are made on the rear panel of all models.
Be sure power to all wires is turned off before proceeding with the installation. High voltage may
be present on the input power wires and relay wires.
A two-terminal connector on the rear panel of all M300 models is provided for power
connection. All M300 models are designed to operate from a 20–30 VDC or a 100 to 240 VAC
power source. Refer to specifications for power requirements and ratings and size power wiring
accordingly.
The terminal block for power connections is labeled “Power” on the rear panel of the transmitter.
One terminal is labeled – N for the Neutral wire and the other + L for the Line (or Load) wire.
There is no earth ground terminal on the transmitter. For this reason the internal power wiring
within the transmitter is double insulated and the product label designates this using the
symbol.
4.2.1 1/4DIN Housing (panel mount)
1 Connection of power supply
2 Terminal for sensors
After connecting the transmitter to power supply circuit, it will be active as soon as the circuit is
powered.
5.2 Placing transmitter out of service
First disconnect the unit from the main power source, then disconnect all remaining electrical
connections. Remove the unit from the wall/panel. Use the installation instruction in this manual
as reference for dis-assembling mounting hardware.