The EATON MTL 9197BLK is a rugged, DIN-rail mounted digital isolator and signal repeater from the renowned MTL (Measurement Technology Ltd.) product line, now part of Eaton's Crouse-Hinds division. It is specifically designed for robust industrial networking, particularly in harsh and hazardous environments.
Key Parameters
1. Core Function:
Device Type: Two-Way, Two-Port, RS-485 Repeater/Isolator.
Purpose: Regenerates digital signals, provides galvanic isolation, and allows network segmentation to extend range and increase the number of allowable nodes on an RS-485 network.
2. Isolation & Protection (Critical Feature):
Galvanic Isolation:
Isolation Rating: 1500V RMS (1 min) between all ports (Side A, Side B) and the power supply.
Benefit: Breaks ground loops, prevents noise coupling, and protects sensitive control equipment from transient surges or faults originating in field wiring.
Intrinsic Safety (IS) Considerations: While not itself an intrinsically safe barrier, it is commonly used to provide isolation between a non-hazardous area control room and an IS-rated RS-485 network in a hazardous area, when used in conjunction with appropriate IS isolators (like MTL 5050 series).
3. Electrical Specifications (RS-485 Data Ports):
Standard: EIA/TIA-485 (RS-485).
Number of Ports: 2 (designated Side A and Side B). Each side can connect to a separate segment of the network.
Data Rate: Up to 460 kbps.
Termination & Bias: Includes user-selectable termination resistors (120Ω) and fail-safe biasing resistors for each port via internal DIP switches. This is crucial for ensuring reliable communication.
Connections: Screw terminals for Data+, Data-, and Ground/Shield for each port.
4. Network Enhancement:
Segment Extension: Effectively doubles the maximum cable length of a single RS-485 segment (typically 1200m at lower speeds) by regenerating the signal.
Node Increase: Increases the maximum number of addressable units (typically 32 per segment) by creating two separate electrical segments.
Wiring Topology: Helps convert a problematic "multi-drop" bus into a more reliable "star" or segmented topology.
5. Power Supply:
Supply Voltage Range: 20 - 30V DC (24V DC nominal).
Power Consumption: Low, typically < 3W.
Connection: Removable screw terminal block.
Reverse Polarity Protection: Yes.
6. Diagnostics & Indicators:
LED Status Indicators:
PWR (Green): Power OK.
TxA / TxB (Yellow): Data transmission activity on Side A and Side B.
Fail (Red): Indicates a fault condition (e.g., loss of signal, short circuit).
No Software Configuration Required: Operation is set via physical DIP switches for termination and bias.
7. Mechanical & Environmental:
Mounting: Standard 35mm DIN rail (EN 60715).
Enclosure Material: High-impact polycarbonate (black, as per BLK suffix).
Protection Degree: IP20 (for mounting inside an enclosure).
Operating Temperature: -20°C to +60°C.
Ambient Humidity: 0 - 95% RH (non-condensing).
8. Certifications & Approvals (Typical for MTL Line):
ATEX / IECEx: Certified for use in Non-Hazardous (Safe) Areas only. (For hazardous areas, it must be mounted in a safe area or within an approved enclosure).
CE Marked.
UL Listed.
CULus Listed.
9. Typical Applications:
Extending and isolating MODBUS RTU (RS-485) networks in industrial plants.
Segmenting large process control networks (DCS, SCADA) in oil & gas, water treatment, and chemical plants.
Isolving ground loop problems between different buildings or equipment grounds.
Protecting PLC and control system COM ports from field-side electrical noise and transients.