MD485
MD485
OrderableRS-485 Multidrop Interface
Pricing
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Configuration
- Interface**-ST -25 to +50C (Ships as 16961, 16675, & 10873)MD485-STPart Number: 42058
- Interface**-XT -55 to +85C (Ships as 33954, 16675, & 10873)MD485-XTPart Number: 42059
Select a configuration to add to your quote
- Model:
- MD485
- Item Number:
- MD485
- Warranty:
- 1 year
Overview
The MD485 is an intelligent RS-485 interface that permits a PC to address and communicate with one or more data loggers over a distance of up to 1200 m. This interface also supports data-logger-to-data-logger communication, callback from a remote data logger, PC-to-printer communications, and digital camera-to-data-logger connections.
Key Advantages
Adds data link possibilities among data loggers, PCs, and sensors
Technical Description
The MD485 includes three ports (RS-232, CS I/O, RS-485) for connecting a PC, a data logger, or another MD485. Any two ports can be used at a time.
The MD485 can be configured to provide transparent communications, MD9 emulation, and PakBus networking. Although the MD485 can emulate an MD9, the MD485 can not be added to an existing MD9 network. PakBus networking requires the data loggers to use the PakBus communications protocol. PC400 or LoggerNet software is used to initiate and control the communications link.
Required Equipment
The MD485 is shipped with the 10873 cable and SC12 cable for connecting it to a PC or data logger. Point-to-point and point-to-multipoint networks use the following equipment:
- PC running PC400 or LoggerNet software
- At the computer site, an MD485 is connected to the computer via a pn 10873 cable.
- At each data logger site, an MD485 is connected either to the data logger’s CS I/O port (not compatible with the CR200(X)-series) or the data logger’s RS-232 port (not compatible with the CR510 or CR10X). The SC12 serial cable connects an MD485 modem to the CS I/O port. The pn 18663 9-pin pin (male) to 9-pin pin (male) null modem cable connects the MD485 to the RS-232 port.
- The CABLE2TP-L Two-Twisted-Pair 22-AWG Cable connects an MD485 to another MD485. Please note that when communicating at maximum distances and high data rates, a cable with polyethylene insulation is recommended.
- CR200(X)-series, CR510, CR800, CR850, CR10X, CR1000, or CR3000 datalogger.
- Power supply
- Environmental enclosure. At each field site, the data logger, power supply, and MD485 should be housed in the enclosure if the equipment is not located in a building.
Powering the MD485
AC power is typically used at the computer site; a pn 15966 wall charger is required. At the field site, the MD485 is powered by the data logger through its CS I/O port. If the MD485 is connected to the data logger’s RS-232 port instead of the CS I/O port, or if the data logger was purchased before 12/97, a pn 14291 Field Power Cable is required. Phone-to-MD485 and spread spectrum radio-to-MD485 networks also require a power supply with a null modem port . An A100 adapter used with a PS150 or PS200 power supply provides this capability. The PS150 or PS200 is recharged via a wall charger or a solar panel.
Benefits
- Compatible with most Campbell Scientific data loggers
- Can be used with a phone modem, Ethernet link, or spread spectrum radio to extend the distance between the data logger and PC
- Increases the distance allowed between a CC5MPX digital camera and a PakBus data logger
- Extends the distance between AVW200 Vibrating-Wire Interfaces for situations where wireless communication is impractical
- Internal buffering ensures that data is not lost during transmission and allows each side to operate at different baud rates
- Includes gas tubes on the RS-485 ports and a ground lug for better surge protection
- Communicates at rates up to 115.2 kbps
Specifications
- Function
- Permits a PC to address and communicate with one or more data loggers over a distance of up to 1,200 m.
- Transmission Distance or Area
- 1,219 m
(4,000 ft) Can increase distance by using more MD485s or combining with spread-spectrum radios, Ethernet, or phone.
- Baud Rates
- 1200, 9600, 19.2k, 38.4k, 57.6k, 115.2k bps
- Voltage
- 12 Vdc
(from data logger or pn 15966 wall charger)
- Surge
- Complies with IEC61000-4-5, test level 3
(±2 kV, 2 Ω coupling impedance)
- Operating Temperature
- -25° to +50°C
(standard)
-55° to 85°C(extended)
- Service Requirements
- CABLE2TP two-twisted pair cables must be installed between networked data loggers and base.
- Maximum Cable Length
- 1,219 m
(4,000 ft)
- Dimensions
- 15.88 x 6.35 x 1.91 cm
(6.25 x 2.5 x 0.75 in.)
- Weight
- 127.6 g
(4.5 oz)
Current Drain
- Standby Mode
- 1.2 mA
- Communicating
- 2 to 7 mA
Power
- Standby Mode
- 14.4 mW
- Communicating
- 24 to 84 mW
ESD
- Air Discharge
- Complies with IEC61000-4-2, test level 4
(±15 kV)
- Contact Discharge
- Complies with IEC61000-4-2, test level 4
(±8 kV)
Accessories
(6)15966
Wall Charger with Barrel Plug
Orderable14291
Field Power Cable, 12 Vdc Plug to Pigtail
OrderableCABLE2TP
22 AWG, 2-Twisted Pair Cable with Drain
Orderable18663
Null Modem Cable, 9-Pin PIn (Male) to 9-Pin Pin (Male)
Orderable8125
Flat-Bladed Screwdriver, 2.5 mm Blade x 50 mm Shaft
Orderable18260
Four-Year Extended Warranty for the MD485
Orderable
Common Accessories
(5)15966
Wall Charger with Barrel Plug
This ac/dc transformer accepts inputs from 90 to 260 Vac @ 47 to 63 Hz, and then outputs 12 Vdc @ 880 mA for use by the MD485 (typically used at the PC where ac power is available). The 15966 is fitted with a cable and barrel plug to connect the transformer to the MD485; cable length is 6 ft.
Orderable14291
Field Power Cable, 12 Vdc Plug to Pigtail
Older dataloggers and dataloggers that are using the RS-232 port to communicate with the MD485 require the 14291 Field Power Cable to power the MD485 via the datalogger. The 14291 allows the MD485 to be powered from a suitable 12 Vdc power supply. It terminates in a barrel plug on one end for connection to the MD485 and two pigtails for connection to the 12V and GND terminals on a power supply. The cable has a 2 foot length.
OrderableCABLE2TP
22 AWG, 2-Twisted Pair Cable with Drain
The CABLE2TP-L is used for MD485-to-MD485 connections. It's a 22-AWG, two-twisted-pair cable with a Santoprene jacket and an aluminum Mylar shield. Cable length is user-specified. Lengths between stations can vary with the needs of the application. Campbell Scientific generally recommends a maximum cable length across the network of less than 4000 ft (1300 m). However, a longer cable length may be possible by using addressing and optical isolation within the network. Chapter 8 of the MD485 manual provides some additional information on configuring large MD485 networks. We also recommend that you consult an applications engineer for assistance in configuring a network of this type.
Orderable8125
Flat-Bladed Screwdriver, 2.5 mm Blade x 50 mm Shaft
If not ordering the datalogger on the same order, you might need this small, flat-bladed screwdriver. The 8125 is extremely useful for opening the guillotine terminals on this interface. The blade is 2.5 mm across and the untapered shaft length is 50 mm. The handle has an approximate length of 9 cm, and features a rotating end-cap that makes the screwdriver easy to rotate.
Orderable18260
Four-Year Extended Warranty for the MD485
The 18260 extends the MD485 standard one-year warranty for an additional four years
Orderable
Replacement Parts
(4)7845
Green 3-Pin Screw Terminal Plug Connector with Threaded Flange
The 7845 is a green RS-485 connector. Two 7845 connectors are attached to every MD485 that leaves the factory.
Orderable505
Screw #6-32 x .375 Pan Phillips
These screws, along with the 6044 grommets, are commonly used together to secure our equipment to the backplates of our enclosures.
Orderable10873
Serial Data Cable, 9-Pin Socket (Female) to 9-Pin Pin (Male)
The 10873 is a serial cable that is useful for connecting the RS-232 port of the datalogger to the 9-pin RS-232 port of a computer. The cable is six feet long.
Orderable6044
Grommet for #6 or #8 Screw
These grommets are commonly used with the 505 screws to secure our equipment to the backplates of our enclosures.
Orderable
Compatibility
Enclosure Considerations
A desiccated, non-condensing environment is required. The MD485 includes built-in keyhole flanges for mounting to the backplate of a Campbell Scientific enclosure.
Combining with Other Devices
The MD485 can be combined with our AVW200-series Vibrating Wire Interfaces, CC640 Digital Camera, Ethernet links, phone modems (including cellular), and spread spectrum radios. Field site equipment should be housed in an environmental enclosure. Information about configuring the other devices is provided in the user manuals.
Power Considerations
AC power is typically used at the computer site; a pn 15966 wall charger is required. At the field site, the MD485 is powered by the data logger through its CS I/O port. If the MD485 is connected to the data logger’s RS-232 port instead of the CS I/O port, or if the data logger was purchased before 12/97, a pn 14291 Field Power Cable is required. Phone-to-MD485 and spread spectrum radio-to-MD485 networks also require a power supply with a null modem port. An A100 adapter used with a PS150 or PS200 power supply provides this capability. The PS150 or PS200 is recharged via a wall charger or a solar panel.
Compatible Products
(7)CR6
High-Capacity Data Acquisition System
OrderableNotesThe CR6 has integrated RS-485.
ENC10/12
Weather-Resistant Enclosure, 10 x 12 inches
OrderableNotes—ENC10/12R
Raised Lid Enclosure, 10 x 12 inches
OrderableNotes—ENC12/14
Weather-Resistant Enclosure, 12 x 14 inches
OrderableNotes—ENC14/16
Weather-Resistant Enclosure, 14 x 16 inches
OrderableNotes—ENC16/18
Weather-Resistant Enclosure, 16 x 18 inches
OrderableNotes—CR350
Measurement and Control Datalogger
OrderableNotesUse a 18663 null modem cable.
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Documents
- Brochure
MD485 RS-485 Multidrop Interface
August 2017
View Document - Manual
MD485 Product Manual (online)
September 2024
View Document - Manual
MD485 RS-485 Multidrop Interface
September 2024
View Document - Technical Paper
Maximum Distances for RS-232 and RS-485
March 2025
View Document
Showing 4 of 6 results
See all DocumentsDownloads
- MD485 OSv05Login required
April 6, 2012
OS and FirmwareCurrent MD485 operating system. Requires the Device Configuration Utility.
- Device Configuration Utilityv2.36Login required
June 22, 2026
Software ApplicationsA software utility used to download operating systems and set up Campbell Scientific hardware. Also will update PakBus Graph and the Network Planner if they have been installed previously by another Campbell Scientific software package. Supported Operating Systems: Windows 11 or 10 (Both 32 and 64 bit)