Extending the Micro800 with Spectrum Controls Plug-In Modules

The Allen-Bradley Micro800 series is a capable platform out of the box, but the base controllers are intentionally lean. They're designed to be extended, and how you extend them matters. Choosing the wrong I/O strategy can mean a panel that's harder to wire, more expensive than it needs to be, or limited in ways you don't discover until you're in the middle of commissioning. For applications that need specialized sensing, communications, or switching capability, plug-in modules are often how the real work gets done.

At HESCO, we help customers build out Micro800 systems across a wide range of industries, from building automation and HVAC to process skids and remote monitoring. One of the most common conversations we have is around I/O strategy; specifically, how to get the right capability into the system without overbuilding or leaving gaps. This article focuses on plug-in modules and walks through what Spectrum Controls offers in their 2080sc lineup. If you're newer to the plug-in vs. expansion distinction, our overview article covers the fundamentals before you dive in here.

The quick summary: Spectrum Controls makes five plug-in modules for the Micro800 platform, covering BACnet communications, universal analog input, thermistor measurement, high-current relay output, and MicroSD-based data logging with a real-time clock. Each one addresses a specific capability gap in the native Rockwell catalog, and all five integrate directly with Connected Components Workbench. Here's what each one does and where it fits.

What Plug-In Modules Make Possible

Plug-in modules mount directly on the Micro800 controller and share its backplane, which keeps latency low and wiring to a minimum. But the more important point is functional: they let a compact controller punch well above its weight for specific tasks without requiring a larger PLC or additional hardware outside the panel.

A few capability areas where plug-ins make a real difference:

• Building automation integration: Many HVAC, lighting, and access control systems run on BACnet, a protocol the base Micro800 doesn't support natively. A plug-in communications module bridges that gap without requiring a separate gateway device, keeping the architecture simple and the cost down.
• Mixed and precision analog sensing: Real-world applications rarely use just one sensor type. A universal analog input module that handles voltage, current, thermocouples, and RTDs on a single module means you're not stacking multiple dedicated modules or compromising accuracy to fit a simpler input type.
• Low-cost temperature measurement: Some applications—particularly HVAC, refrigeration, and food processing—rely heavily on NTC thermistors. These sensors are inexpensive and widely used, but they typically require signal conditioning before connecting to standard analog inputs. A dedicated thermistor module eliminates that hardware entirely.
• High-current switching: The Micro800's onboard relay outputs are fine for light loads, but applications like boiler control, heating elements, and large contactors need more. A plug-in module rated for 10 A per channel handles those loads directly, without external relays adding complexity to the panel.
• Data logging and recipe management: Process skids, remote stations, and batch applications often need to log data locally, especially when network connectivity isn't guaranteed. A MicroSD-based memory module with a real-time clock enables timestamped data logging, recipe storage, and controller backup without a PC on site.

The Spectrum Controls 2080sc Lineup

Spectrum Controls is a Rockwell Automation Technology Partner, and their 2080sc series was built specifically for the Micro830, Micro850, and Micro870. All modules are compatible with Connected Components Workbench and carry UL/cUL listings with Class I, Division 2 hazardous location ratings where applicable. Here's a top-level look at each module.

2080sc-BAC: BACnet Communications Module

The 2080sc-BAC gives the Micro800 a direct presence on BACnet networks, with both serial (MS/TP via RS-485 or RS-232) and Ethernet (BACnet/IP) on a single module. It supports five standard BACnet objects and conforms to the ASHRAE-defined AAC communication standard, making it a straightforward fit for building automation applications including HVAC, lighting control, fire detection, and access control. Find it on our webstore here.

• Two-channel design: one serial channel and one 10/100 Ethernet channel, covering both network types without needing separate modules.
• RTC backup: onboard real-time clock with a minimum 72-hour power backup, so timestamps stay accurate through brief outages.
• Baud rates: 1200 through 76.8K, giving you flexibility across older and newer BACnet serial installations.

2080sc-IF4U: 4-Channel Universal Analog Input Module

The 2080sc-IF4U is built for applications where sensor types vary by channel or change over time. It supports voltage, current, thermocouple (J, K, T, E types), and RTD inputs—up to four channels of mixed analog in a single module slot. For engineers who would otherwise need separate thermocouple, RTD, and analog input modules, this consolidation is a significant practical advantage. Find it on our webstore here.

• Fifteen input types: covering the most common industrial sensor standards, all individually configurable per channel through CCW.
• Channel-selectable filtering: five filter frequencies from 4 Hz to 470 Hz let you balance update speed against noise rejection on a per-channel basis.
• Cold junction compensation: included for thermocouple inputs, so you don't need external reference hardware.
• Input protection: ±30 VDC continuous overvoltage and 28 mA overcurrent, providing a meaningful buffer against wiring errors in the field.

2080sc-NTC: 4-Channel Thermistor Analog Input Module

Where the IF4U covers a broad range of sensor types, the 2080sc-NTC focuses specifically on NTC thermistors and 2-wire resistance inputs. It's the right choice when your application leans heavily on thermistors—refrigeration monitoring, HVAC zone sensing, or food processing—and you want direct sensor connection without external signal conditioning. The module delivers fully linearized temperature data and is factory calibrated for accuracy. Find it on our webstore here.

• Resistance range: 250 ohms to 250 Kohms[CD1] [DG2] , covering a wide span of NTC thermistor types without additional configuration.
• 500 VDC field wiring-to-backplane isolation: provides meaningful protection in environments where electrical noise is a concern.
• Update times from 20 ms to 495 ms: selectable per channel depending on whether speed or noise rejection is the priority.

2080sc-OW2IHC: 2-Channel High Current Relay Output Module

The 2080sc-OW2IHC handles resistive and inductive loads up to 10 A per channel across a wide voltage range, from low-voltage DC control up to 250 VAC. The Form A normally open relays are well suited for applications like boiler control, temperature controllers, and timers where the onboard outputs on the base controller aren't rated for the load. LED indicators on each channel give you quick visual confirmation of relay state during commissioning and troubleshooting.

• 10 A per channel: rated for both DC (5–30 VDC) and AC (125 or 250 VAC), making it versatile across control panel configurations.
• Output power rating: up to 2500 VA at 250 VAC, handling substantial inductive loads without external relay hardware.
• Switching time: 10 ms maximum, 5 ms typical—fast enough for most control applications without special timing considerations.

2080-SDMEMRTC-SC: MicroSD Memory Module with Real-Time Clock

The 2080-SDMEMRTC-SC addresses a practical gap in standalone and remote applications: how do you log data, manage recipes, and update firmware when there's no PC nearby? This module adds a MicroSD card slot (supporting 4, 8, 16, and 32 GB cards, sold separately) and a real-time clock directly to the controller. It's particularly valuable for process skids, remote monitoring stations, and batch applications where local data storage and timestamping are requirements, not nice-to-haves. Find it on our webstore here.

• Data logging at up to 0.5-second intervals: enough capacity for dense process monitoring with support for up to 10 data sets of 128 variables each, and up to 50 files per day.
• Recipe storage: up to 10 recipe sets with 128 variables each, eliminating the need to connect a PC for batch changeovers.
• Firmware updates via SD card: technicians can update controller firmware in the field without a laptop, reducing service time on remote or hard-to-reach installations.

The Right Module for the Right Job

Spectrum Controls' 2080sc lineup fills real gaps in the native Micro800 catalog: BACnet connectivity, mixed analog sensing, thermistor measurement, high-current switching, and local data logging. Each module is purpose-built for a specific function, which means you're not paying for capability you don't need or compromising on performance to fit a more generic solution.

If you're working through a Micro800 application and want help identifying which plug-in modules belong in your system, reach out to the HESCO team. We'll help you spec the right combination of native Rockwell and Spectrum Controls hardware for your specific requirements. And when you're ready to look at the expansion I/O side of the equation, our article on Spectrum Controls' 2085 expansion modules covers what's available there.