Zen IoT Edge Processing Interface

Zen IoT Edge Processing Interface

4x isolated universal inputs, 2x non-isolated 4-20mA inputs, expandable IO. Store & Forward record buffer, RTC time stamp, RS485 ModBus RTU master/slave interface, TLS 1.2

Additional information

Weight 0.694 kg
Dimensions 11.8 × 16.9 × 5.9 cm
Power Supply

HV – 85-265 V AC/DC
LV – 10-32 V DC

Wireless comms

No wireless comms
CM1 – Cell modem (eMTC) LTE Cat-M1
WIF – WiFi (801.11)

IO Expansion (additional to base model channels)

UI4 – 4x Universal inputs (isolated)
UI8 – 8x Universal inputs (isolated)
UI12 – 12x Universal inputs (isolated)
PI16 – 16x 4-20mA inputs (non-isolated)
UI6E4 – 6x Universal inputs (isolated), 4x 4-20mA output (isolated)
PI8E8 – 8x 4-20mA input (non-isolated), 8x 4-20mA output (isolated)

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What it does

Allows standalone industrial hardware to be connected to the Cloud. Can perform calculations prior to transmitting this data. Requires Bridge Key for programming. Part of the Define Instruments IoT machine monitoring solution.

Connect your standalone hardware to the Cloud with this IoT gateway with analog inputs

The Zen IoT is a gateway device for connecting standalone equipment (PLCs or other discrete control systems) to the Cloud.

Use it also for Edge Processing: when you need to collate data, perform calculations and send the results to the Cloud. The Zen IoT allows this with ease. Calculations are performed within the device and resulting data communicated via a choice of Cloud connection options.

Data visibility for better machine performance

The Zen IoT collates signals from industrial equipment for processing and publishing to the Cloud. It enables visibility for determining machine health or process efficiency.

Zen IoT Smartphone Dashboard

Convert process signals direct to wireless

While most devices only convert Modbus to wireless, the Zen IoT converts process signals straight to wireless! No additional devices needed. The unit features industrial grade analog and digital I/O, with 4–20mA, RTD, TC and many more available.

Get the datasheet

Zen IoT Datasheet A4 v6

Integrates with all your existing equipment

It’s now simpler than ever to connect your industrial equipment to the Cloud, as the Zen IoT supports a wide range of communication protocols.

Modbus is supported, as well as new IoT comms like MQTT. Physical connections include WiFi (801.11) or (eMTC) LTE Cat-M1 and RS485. Potential applications include AMR (Automatic Meter Reading), remote monitoring of assets, and data collation and transmission.

Available in Custom configurations

This product is available in custom configurations for OEMs and high volume orders. If you have a difficult application, please call 1-888-652-4757 so we can assist you.

Uses extra layer of IoT security

Privacy and security are big concerns but the Zen IoT gives you peace of mind. It has its own WiFi port and connects with an extra layer of security: Transport Layer Security (TLS). Additionally it has an ethernet port which uses only Modbus TCP so the port cannot be hijacked for any other communication uses.

Additionally, the Zen IoT offers a flexible logic engine which can be programmed with a powerful scripting language for custom applications.

Try Before You Buy!

Use the product simulator inside our free WorkBench software to demo how this instrument works.

Bridge Key Required!

In addition to this software a Bridge Key is required for the configuration of this product.

You must order one unless you already have one from a previous product purchase.

Uses extra layer of IoT security

  • Up to 22 analog inputs
  • Up to 40 digital input/outputs
  • 8 isolated process outputs (4-20mA)
  • Up to 7 relay outputs
  • RS484 ModBus RTU master/slave interface
  • Local display (RS232C) interface port
  • AC mains and 24V low power operation
  • Application logic and math functions
  • Define Cloud Services (DCS) connection
  • MQTT with Transport Layer Security (TLS 1.2)
  • Data record store and forward record buffer
  • Easy USB programming via PC using Define WorkBench software, requires Bridge Key

Cloud Connection Options:

IoT Wifi

WiFi (801.11)

Enables LOS transmission of up to 1476ft (450m) using the supplied 3dBi wireless antenna.

IoT Cellular

(eMTC) LTE Cat-M1

4G cellular interface for Internet of Things (IoT) and machine-to-machine (M2M) communications

The Zen IoT is preconfigured to connect to Define Cloud Services (DCS). Custom connection is available to your own or third party server. Cloud communication is secured using TLS and uses MQTT IoT service transfer protocol.

Define WorkBench configures the Zen IoT for analog and digital inputs, alarms, totalizers and counters, custom scaling for linearization and scale setup. The cloud interface module configures data transfer to a cloud server and sends JSON packets containing the industry standard SenML (Sensor markup language) data.

5 Year WarrantyRCM E2180CE
5 Year WarrantyRCM E2180CE



Input configuration
ZEN6: 4x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated)
UI4: 8x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated)
UI8: 12x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated)
UI12: 16x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated)
PI16: 4x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated) plus 16 partially isolated 4-20mA inputs
UI6E4: 4x Universal inputs (isolated) plus 2x 4-20mA inputs (non-isolated)

Input isolation: 2,500V AC 1 minute between all input channels

Isolation test voltage: 1000V DC for 1min (Analog input to digital output, Analog input to analog input)

Excitation: 24V DC @200mA maximum. Total on all +24V output pins.

Resolution: 16 bits

Accuracy: <±1.0% fso (unless otherwise stated in input)

Accurate to: <±0.1% fso (unless otherwise stated in input)


Power supply: 85-265V AC/DC (HV) 10–30V DC (LV)

General Specifications

Noise immunity: (CMRR) 160dB tested at 300V RMS 50Hz

RF immunity: <±1% effect fso

Permanent memory: (E²ROM) 100,000 writes per input parameter

Linearity & repeatability: <±0.1%

Channel Separation: 125db minimum

Thermocouple Input

Thermocouple types
B= 32 to 3272°F (0 to 1800°C)
E= -328 to 1292°F (-200 to 700°C)
J= -328 to 1832°F (-200 to 1000°C)
K= -328 to 2300°F (-200 to 1260°C)
N= -328 to 2372°F (-200 to 1300°C)
R= 32 to 3092°F (0 to 1700°C)
S= 32 to 3092°F (0 to 1700°C)
T= -328 to 752°F (-200 to 400°C)

Input impedance: 500KΩ

T/C lead resistance: 100Ω max

Cold junction compensation: 14 to 140°F (–10 to 60°C)

CJC drift: 0.02°c °c typical for all

Accuracy: 0.1% of FSO ±1°C typical

Sensor open: Upscale

RTD Input

RTD input type: Pt100 3 wire RTD DIN 43760: 1980 Pt1000 3 wire RTD standard

Range: -328–572°F (-200–300°C), 0.02°F (0.01°C) resolution -328–1472°F (-200–800°C), 0.1°F (0.1°C) resolution

Lead wire resistance: 10Ω/lead max recommended

Sensor current: 0.6mA continuous

Sensor fail: Upscale

Accuracy: -328–572°F (-200–300°C) = ±0.1°C;
-328–1472°F (-200–800°C) = ±0.3°C

Ambient drift: 0.003°C/°C typical

Current Input

Range: 0–20mA, 4–20mA

Input impedance: 45Ω

Max over-range: Protected by PTC to 24V DC

Linearity & repeatability: 0.1% FSO max

Accuracy: 0.1% FSO max

Channel separation: 0.001% max

Ambient drift: 0.003%/°C FSO typical

RF immunity: 1% effect FSO typical

Voltage Input

Ranges: ±200mV, –200mV to 1V, 0–10V, 0–18V

Input impedance: >500KΩ on all ranges

Maximum over voltage: 24V DC

Linearity & repeatability: 0.1% FSO max

Accuracy: 0.1% FSO max

Channel separation: 0.001% max

Ambient drift: 0.003%/°C FSO typical

RF immunity: 1% effect FSO typical

Digital Pulse Input

Frequency range: 0–2500.0Hz

Fast counter range: 0–2500.0Hz

Sensors: Open collector (NPN, PNP), TTL or Clean Contact

Frequency resolution: 0.1Hz

Debounce counter range: 0–50Hz max

Counter register output: 32 bit

Accuracy: ±0.5%

AC Current Sensor Input

Sensor type: Current transformer ACCS-420, ACCS-420-L and ACCS-010

Amperage range: Header selectable ACCS-420/010= 100/150/200A ACCS-420-L= 10/20/50A

Overload (continuous): ACCS-420/010= 175/300/400A ACCS-420-L = 80/120/200A

Output: (Representing 0–100% of full scale input range) ACCS-420(-L)= 4–20mA DC loop powered ACCS-010= 0–10V DC

Power supply: ACCS-420(-L)= Loop powered, 15–36V DC ACCS-010= Self powered

Accuracy: 1% of full scale

Response time: 250ms (10–90%)

Isolation voltage: 2,000V

Frequency: 50–60Hz

Potentiometer Input

Potentiometer input: 3-wire

Excitation voltage: Variable

Potentiometer resistance: <2kω low pot,>2kΩ high pot

Field programmable zero: 0–90% of span

Field programmable span: 0.1–100%

Linearity & repeatability: <±0.05% fso

Response time: 100msec

Ambient drift: <50ppm

Attenuator Input

Attenuator type: Define Instruments HVA-1000, differential resistive attenuator

Max input voltage: 1000V DC

Attenuation factor: 1000 ±0.1%

Input impedance: 3.8MΩ

Output impedance: 3.8kΩ

Ambient drift: 50ppm/°C max

Relay Output

Number of relay outputs: 3

Relay output type: 1 x Change over Form C Relay (15A 250V AC or 15A 30V DC) 2 x Form A Relays (3A 250V AC or 3A 30V DC)

Comm Port(s)

Protocols: Modbus RTU, RS485, RS232 or Define ASCII

Default comm port: RS485 / RS232 auto-select. Selectable baud rate 2400–230000 baud. Format 8 bit, no parity, 1 stop

Isolation test voltage: 1000V DC for 1min (Comm to analog input, Comm to digital input/output) Optional additional comm

(front panel): Select WiFi, Ethernet IoT or RS485/232 (auto-detecting)

Digital Inputs

Number of digital inputs: 4

Input types: NPN, PNP, Clean Contact, Voltage 2–30V DC

Functions: Status, up counter, up/ down counter with direction, debounced counter, frequency, gated frequenc

Counter register output: 32 bit

Frequency range: 0–10,000Hz

(Reduced to 0–1,000Hz in Sleep Mode)

Threshold: 1.2V typical

Debounce counter range: 0–100Hz

Isolation: Not isolated to power supply or analog inputs

Data Logging

Real-time clock: RTC time base UTC. Local time in device with automatic daylight savings adjustment

Data logging: 31,744 samples with up to 30 parameters plus time stamp per sample. 32MB capacity.

Datalog retrieval: Simple data log retrieval and visualization, using Define WorkBench


USB programmable: Via ‘PC Setup’ port using Bridge Key USB programmer (sold separately)

Define WorkBench: Simple configuration and datalog retrieval using Define WorkBench


Casing: DIN 35 rail mounting; Material: ABS inflammability V0 (UL94); Phoenix type removable screw terminal connectors

Dimensions (H x W x D): ZEN6, ZEN6-UI4 = 3.98 x 1.73 x 4.72″ (101 x 48 x 120mm)* UI8, UI12, PI16, UI64 = 3.98 x 2.87 x 4.72″ (101 x 73 x 120mm)* *Excludes antenna and connectors Required mounting height With Antenna= 4.65″ (118mm), WiFi model only

Environmental Conditions

Operating temperature: –40 to 176°F (–40 to 80°C)

Storage temperature: –40 to 176°F (–40 to 80°C)

Operating humidity: 5–85% RH max, non-condensing

Certifications & Compliances

EN 61326-1 2006

UL listed: File listing pending

EMC: Emissions EN 61326-1 2006 Class A; Immunity EN 613265-1 2006 Industrial Locations; EN50581: 2012 RoHS; Safety EN 61010, 1:2010


Zen IoT Manual (Zen6) 22V05, 13-Oct-2022 | (1.56 MB)
Zen IoT Datasheet A4 v6, 11-Dec-2019 | (812 KB)
Zen IoT Datasheet US Letter v6, 11-Dec-2019 | (811 KB)
Zen IoT Register Supplement 16V04, 11-Oct-2016 | (2.7 MB)


Define WorkBenchDefine WorkBench

Simple software to program your Zen series or edge processing device Use Define WorkBench to simulate, configure and view data for all Zen series control stations and Nimbus IoT Gateways, including:

With a user-friendly, uncluttered design, WorkBench offers a simple interface for setting up and scaling your unit, as well as retrieving and graphing your datalog. N.B. Version 3 features Simulation Mode and is only compatible with legacy ZEN-16 firmware 2.0.0 and later.

Define WorkBench

Order Codes


Base configuration: MQTT cloud service interface – TLS security layer, store and forward record buffer, RTC data time stamp, 4x isolated universal inputs (TC/RTD/V/mA/SCII)
Power supply
-HV 85-265V AC
-LV 10-32V DC
Comms Configuration
No wireless communication
-CM1 Cellular modem (eMTC) LTE Cat-M1
-WIF WiFi (801.11)
Optional analog IO expansion
No additional analog IO
-UI4 ADD 4x Universal input (isolated)
-UI8 ADD 8x Universal input (isolated)
-UI12 ADD 12x Universal input (isolated)
-PI16 ADD 16x process (4-20mA) input (non-isolated)
-UI6E4 ADD 6x Universal input (isolated), 4x process (4-20mA) output (isolated)
-PI8E8 ADD 8x process (4-20mA) input (non-isolated), 8x process (4-20mA) output (isolated)

All prices are in US Dollars. For pricing in other currencies, please contact us.