Rosemount 702 Wireless Discrete Transmitter
Overview
The Rosemount 702 Wireless Discrete Transmitter is an installation-ready device that brings switch and on-off signals into a WirelessHART network without running new cable. It offers dual-channel discrete input, configurable discrete input or output, and a dedicated plunger arrival option, with logic for limit contact and opposing contact applications. Momentary inputs are captured continuously between wireless updates, so short events are not missed, and the self-organizing network delivers more than 99 percent data reliability according to the Emerson data sheet.
Seven Star LLC supplies the Rosemount 702 to oil and gas operators, utilities and process plants in Oman and across the GCC. Remote wellheads, tank farms and long pipeline corridors in the region often have discrete points that were never wired back to the control room, and our Muscat engineering team helps customers select the right Rosemount 702 configuration, antenna and certification from the official Rosemount 702 datasheet.
Operating Principle
The transmitter monitors dry contacts wired to its screw terminals. A contact is read as open above 100 kilo-ohms and closed below 5 kilo-ohms. At each wireless update, the device reports the current discrete state and an accumulating count of close-open cycles, so a valve that strokes or a pump that starts between updates is still recorded. The update rate is user selectable from 1 second to 60 minutes, and a latching time from 1 second to 10 minutes can be set so that brief events are held long enough to be reported to the host.
Communication uses IEC 62591 WirelessHART on IEEE 802.15.4 radios in the 2.4 GHz ISM band, sliced into 15 channels with time-synchronized channel hopping. Each Rosemount 702 also acts as a router for its neighbors, and the self-healing mesh manages multiple communication paths, so if an obstruction blocks one path the data continues through another. Encryption, authentication, verification, anti-jamming and key management protect the data, which is received only by the wireless gateway.
Engineering Design of the Rosemount 702
The device uses a dual compartment housing in low-copper aluminum or stainless steel, rated NEMA 4X and IP66/67, with a 1/2-14 NPT conduit entry. It can be attached directly to a switch, or mounted remotely using the universal L bracket for a two inch pipe. Antenna options include an integrated external antenna, an extended range antenna, a remote antenna and a high-gain remote antenna for difficult radio paths, and an optional LCD shows the discrete state and diagnostic information at each update.
Power comes from an Emerson SmartPower module containing lithium-thionyl chloride cells in a PBT enclosure. The intrinsically safe module is field replaceable with keyed connections that prevent incorrect installation, and gives a rated life of ten years at a one-minute update rate. The aluminum Rosemount 702 weighs about 2.0 kg without display, and the stainless steel version about 3.6 kg. Intrinsic safety and Zone 2 approvals cover ATEX, IECEx, USA, Canada and several other regions.
Key Features
The following Rosemount 702 capabilities are drawn from the Emerson product data sheet.
- Provides dual channel discrete input, configurable discrete input or output, and plunger arrival measurement options.
- Detects momentary discrete inputs of 10 ms or longer and keeps a cycle count up to 999,999.
- Drives discrete outputs rated 26 Vdc and 100 mA with typical on resistance of 1 ohm on option 42.
- Offers user-selectable update rates from 1 second to 60 minutes and latching times from 1 second to 10 minutes.
- Runs up to ten years on a field replaceable intrinsically safe power module at a one-minute update rate.
- Integrates through gateways using OPC, Modbus TCP/IP, Modbus RTU and EtherNet/IP, with native DeltaV and Ovation integration.
- Operates from –40 to 85 °C without display and is unaffected by high pipeline vibration per IEC 60770-1.
- Supports universal safety shower and eyewash kits with UL or CSA switches for uninsulated and insulated pipe.
Industrial Applications
In Oman the Rosemount 702 is a practical way to add monitoring to assets spread across large areas. Typical points include open and closed limit switches on manual and on-off valves, run status of pumps and fans, alarms from pressure, temperature and level switches, safety shower and eyewash activation, gate and hatch positions, and plunger arrival on gas wells. Because installation needs no signal cable, the transmitter suits brownfield upgrades in Sohar and Salalah, remote facilities in the interior, and temporary monitoring during turnarounds. Paired with a vibrating fork switch, it can also report a wireless high level alarm from a remote tank.
Seven Star LLC supports wireless instrumentation projects across Oman and the GCC with network planning input, configuration and delivery. The Rosemount 702 shares the same network as the Rosemount 648 wireless temperature transmitter, can carry the contact from a Rosemount 2140 vibrating fork level detector, and is configured in the field with the Emerson 475 Field Communicator.
It also pairs with the Rosemount 2120 vibrating fork level switch.
Technical Specifications
Published Rosemount 702 specifications from data sheet 00813-0100-4702 are listed below.
| Parameter | Specification |
|---|---|
| Model | Rosemount 702 Wireless Discrete Transmitter (702DX) |
| Measurement options | 32: dual discrete input with momentary detection and counts; 42: dual input or output, configurable; 52: plunger arrival detection |
| Discrete input | Single or dual SPST dry contacts or single SPDT dry contact |
| Switching threshold | Open >100 kΩ; closed <5 kΩ |
| Discrete output (option 42) | 26 Vdc, 100 mA maximum; on resistance typically 1 Ω |
| Wireless protocol | IEC 62591 WirelessHART, 2.4 GHz |
| Update rate | 1 second to 60 minutes, user selectable |
| Power module life | 10 years at one-minute update rate (reference conditions) |
| Housing | Dual compartment, low-copper aluminum or stainless steel |
| Enclosure rating | NEMA 4X and IP66/67 |
| Conduit entry | 1/2-14 NPT |
| Operating temperature | –40 to 85 °C; –20 to 80 °C with LCD |
| Humidity | 0 to 100 percent relative humidity |
| Weight | 2.0 kg aluminum; 3.6 kg stainless steel (without LCD) |
| EMC | EN 61326 and NAMUR NE-21 |
How to Order
For a formal RFQ on the Rosemount 702, send Seven Star LLC the measurement option, housing material, hazardous area certification, antenna type, display and bracket needs, and whether a safety shower kit or extended warranty is required. Our instrumentation division will confirm the model code against the Rosemount 702 datasheet, confirm availability and lead time, provide the data sheet for download and give engineering support from Muscat for wireless discrete monitoring projects in Oman and the GCC.
- Datasheet Emerson Rosemount 702 Wireless Discrete Transmitter Product Data Sheet 00813-0100-4702, Rev LD, December 2025 Download
Rosemount product families on this page
Pressure includes the 3051 in its variants (3051T in-line, 3051L for liquid level, 3051CF DP flowmeter and the 3051SMV MultiVariable transmitter), the 2051 and 1199 diaphragm seal systems. Level instruments are the 3300 guided wave radar, the 5408 non-contacting radar and the 2120 vibrating fork switch. Temperature is covered by the 248 and 644 head mount transmitters and the 848T high density transmitter for multiple sensor inputs. The 8800D vortex flowmeter and the 702 wireless discrete transmitter are also listed, along with liquid analysis sensors.Where Rosemount instruments are used
These are standard instruments in oil and gas production, refining, petrochemical, power and water plants. Typical duties are line and vessel pressure, differential pressure flow across orifice plates, tank and separator level and interface, and temperature measurement on pipes, reactors and rotating equipment.Ordering Rosemount transmitters: what we need
Send the complete model string and the serial number from the nameplate; a photo is ideal. Every character of the string selects something: range, output, materials of the isolating diaphragm and flange, process connection, housing, approval and options. If you are specifying a new point, give the measured variable and span, process fluid, pressure and temperature, connection, output (4-20 mA HART, FOUNDATION Fieldbus or wireless), display and hazardous area approval. For remote seals add flange size, rating and capillary length.Browse Rosemount products by category: Pressure Instrumentation, Temperature Instrumentation, Level Transmitter, Liquid Analysis Sensors, Flowmeters.
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