Product Details
The Honeywell 2MLL-CH2A, also cataloged as the 2MLL-CH2A Serial Communication Interface Modules, operates as a dedicated hardware component for serial data protocol handling within Master-K platform PLC networks. It establishes dual asynchronous channels to route field device data via RS-232C and RS-422/485 serial interfaces directly into the central processor memory map.
Hardware Specifications
| Parameter | Specification |
|---|---|
| Model | 2MLL-CH2A |
| Brand | Honeywell |
| Origin | Industrial Standard Assembly |
| Weight | 119 g |
| Dimensions | Standard Rack Slot Width |
| Operating Temp | 0 to 55 deg C |
| Power Consumption | 310 mA (Backplane 5 VDC) |
| Physical Interface | 1 Channel RS-232C, 1 Channel RS-422/485 |
| Transmission Speed | 300 to 115200 bps |
| Transmission Distance | RS-232C: 15 m; RS-422/485: 500 m max |
| Supported Protocols | Modbus RTU/ASCII Slave, P2P Master, User-Defined |
4-20 mA HART Loop Protocol & DCS Integration
While operating primarily as an asynchronous serial processor, the module enables protocol mapping interfaces that interact with field instrument networks. Integrated channel-to-channel isolation safeguards backplane communications from electrical noise, common-mode ground potential shifts, and transient surges originating on external RS-422/485 multidrop lines. This isolation barrier prevents loop corruption and maintains signal processing integrity across long line distances when transmitting digitized process values from legacy 4-20 mA transmitters or serial gateway bridges.
Frequently Asked Questions
Q: What is the backplane current draw for the 2MLL-CH2A module during active transmission?
A: The module draws a continuous current of 310 mA from the internal 5 VDC backplane bus power supply. Ensure the base rack power supply unit has sufficient overhead capacity prior to adding channels.
Q: How are network parameters and protocol selections assigned to the dual serial ports?
A: Parameter assignments including baud rate (300 to 115200 bps), data bits (7 or 8), parity, and protocol modes (Modbus RTU/ASCII or P2P) are configured via the SoftMaster-NM programming environment and flashing memory down to the module interface.
Q: What topology configuration options exist for the RS-422/485 channel?
A: The RS-422/485 port supports 1:1, 1:N, and N:M multi-drop networking configurations with station numbers assigned from 0 to 31, servicing up to 32 network nodes across a maximum distance of 500 m.
Field Installation Guidelines
- Power down the PLC rack chassis completely before inserting or removing the module from the backplane slot.
- Verify that shield wires for RS-422/485 serial cables are grounded at a single point to prevent ground loops from introducing serial framing errors.
- Keep RS-232C cable runs within the 15 m physical length limit to avoid signal attenuation and parity faults at higher baud rates.
- Ensure terminating resistors (typically 120 ohm) are enabled or connected across the physical end-nodes of the RS-485 differential bus line.
Additional Information
- 100% Genuine Parts: All products are original and authentic, ensuring reliable industrial performance.
- 30-Day Refund Guarantee: Return any in-stock item within 30 days in original, unopened packaging for a full refund (excluding shipping and fees).
- 12-Month Warranty: Covers defects in materials or workmanship; excludes misuse, normal wear, or unauthorized modifications.
- Worldwide Shipping: We ship via USPS, UPS, FedEx, and DHL. Delivery times vary by country and may be subject to customs or import fees.
- Support & Contact: Technical and warranty assistance is available anytime. Contact us here: Contact.
- Purchase Guidance: Check product specifications and compatibility carefully before ordering to ensure proper application.
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