ELK-M1DBH Data Bus Hub — Installation Guide

Installation guide for the ELK-M1DBH Data Bus Hub — an accessory that connects multiple CAT5/CAT6 home run cables to the ELK M1 Control panel, organizing the RS-485 data bus into a clean daisy-chain wiring scheme.

Application

The ELK-M1DBH is the ideal way to connect multiple home run cables to the M1 Control. It's designed for CAT5 or CAT6 cables with RJ45 plugs on the ends. The M1DBH handles series-connecting the data lines (A & B) and provides a clean, organized method for managing the data bus wires between the M1 and all keypads/zone expanders on the system.

Features

• Designed for multiple home run cables
• Internally connects Data A & B lines from the previous device into the next device out (daisy-chain)
• Provides up to nine (9) data bus connections
• Multiple hubs may be connected together for expansion
• EOL (end-of-line) bus termination can be done on-board — an RJ45 terminating resistor plug is included
• Comes with a mounting plate for structured wire boxes

Specifications

Mounting

The M1DBH comes pre-assembled on a 3" structured wiring plate (ELK-SWP3), which mounts inside any ELK Structured Wiring Enclosure using four (4) black push-pin style fasteners. The board can also be removed from the plate and mounted separately using double-faced tape.

Installation Steps

1. Connect the +VKP, Data A, Data B, and Neg data bus terminals from the M1 board to the top four (4) input terminals on the M1DBH board using a 4-conductor cable.
2. Pull CAT5 cable from each data bus device to the control.
3. Terminate each CAT5 data bus cable with an RJ45 plug using the appropriate crimping tool, wired to the 568A standard. (RJ45 plugs are not included, since brand and crimping tool preference varies by dealer.)
4. Following the 568A color codes, connect each CAT5 cable at every device. The Pos & Neg wires connect singularly to the Pos/Neg terminals of the keypad or zone expander. The Data A & B lines connect along with a "return" wire so data travels back to the M1DBH and on to the next device — putting the data lines in a series/daisy-chain circuit. The very last device in the chain requires a terminating resistor (step 5) — this is critical given the high speed of the M1's RS-485 bus.
5. Plug each data bus cable into its own RJ45 jack on the M1DBH, starting at J1. If there are more than 9 data bus cables, add a second M1DBH and connect the included short CAT5 jumper from J9 on the first M1DBH to J1 on the second — giving 8 usable jacks per board (16 total across two boards). Additional M1DBH boards can be chained for more capacity.
6. Insert the included EOL (end-of-line) terminating resistor plug into the first unused jack. This places a 120 Ohm resistor across the A & B data return lines from the last wired device, properly terminating the bus.
7. To connect more than 9 data bus runs, additional M1DBH units can be daisy-chained together using a "crossover" cable (built from CAT5/CAT6 wire and 2 RJ45 connectors, with the Wht-Org and Wht-Grn pairs swapped). Plug one end into J9 on the first M1DBH and the other end into J1 on the next.

Wiring Reference

• M1 RS-485 Data Bus terminals: +VKP (Red), Data A (Green), Data B (White), Neg (Black)
• Maximum total data bus length: should not exceed 4,000 feet. When calculating total length, count each home run to the M1DBH twice (×2), since the data lines run out and back. Maximum number of data bus devices varies by control model.
• CAT5/CAT6 pin colors at the keypad end: Pin 1 Wht/Grn, Pin 2 Grn/Wht, Pin 3 Wht/Org, Pin 4 Blue/Wht, Pin 5 Wht/Blue, Pin 6 Org/Wht, Pin 7 Wht/Brn, Pin 8 Brn/Wht. The spare pair (Wht/Blue, Blue/Wht) can be used to double up power or for other purposes.

ELK Products, Inc. — PO Box 100, Hwy. 70W, Hildebran, NC 28637, USA | Voice: 828-397-4200 | Fax: 828-397-4415 | www.elkproducts.com | info@elkproducts.com (Doc ref: 021706)