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Guide

Wiring a door to a Mercury MP1501

To wire a door to a Mercury MP1501, land the reader on TB1301, door contact and exit button on IN1 and IN2, the maglock on K1 NC, and run it on PoE or 12 V.

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Applies to Mercury MP1501 · installation guide PLT-07669 rev A.3
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Quick answer

Reader on TB1301, door contact on IN1 (TB1400-1/2), exit button on IN2 (TB1400-3/4), maglock on relay K1 C and NC (TB1401-2/3), and power over PoE on J1000 or 12 V DC into TB300-3 and TB300-4.

The steps and the reason are below.

The MP1501 controls one door. It has two reader ports, for a reader on each side of the door, two inputs and two relays, and it fits in a 3-gang wall box. It runs on PoE, PoE+ or 12 V DC, and it has a 12 V AUX output, so one network cable can power the board, the reader, the exit button and the lock. The diagrams below wire a door that way, then with the lock on its own battery-backed supply, then with OSDP readers.

Which terminals the door uses

An MP1501 door uses one reader port, two inputs and one relay, and the host software decides which does what. This is the usual layout:

Job MP1501 terminals
Entry reader Reader port 1 · TB1301
Exit reader, optional Reader port 2 · TB1300, powered from TB300-1 and -2
Door contact IN1 · TB1400-1, -2
Exit button IN2 · TB1400-3, -4
Lock Relay K1 · TB1401-1, -2, -3
Spare Relay K2 · TB1401-4, -5, -6
Power PoE or PoE+ on J1000, or 12 V DC on TB300-3 and -4

Check the power budget first

Reader port 1’s VO and the AUX output, which also feeds any reader on port 2, share one budget. How big it is depends on what powers the board:

The board runs on Left for readers and AUX
PoE (802.3af) 625 mA
PoE+ (802.3at) 1.25 A
12 V DC on TB300-3 and -4 1.25 A
  • Reader port 1 gives 600 mA at most, within that budget.
  • Anything in the micro USB port, such as a USB network adapter, takes 270 mA off it.
  • PoE+ means a switch port or injector that delivers 802.3at, 25.5 W.
  • A local supply has to give 12 V, within 10%, and at least 1.8 A, over an 18 AWG pair. Mercury specifies a power-limited (UL Class 2) supply. Use PoE or the local supply, not both.
  • Mercury’s hardware drawing marks one mounting hole as the board’s earth point. Bond it to earth.

Add up the reader, the exit button and the lock from their datasheets, using their maximum currents, not the idle ones. If the total fits, the board can power the whole door, as in the first diagram. If it doesn’t, if the lock runs on 24 V, or if the door has to stay locked when the board loses power, give the lock its own battery-backed supply, as in the second.

Wire the door with everything powered from the board

Here the board runs on PoE+ (or plain PoE, if the budget fits), or on a local 12 V supply on VIN (dashed), and its AUX output on TB300-1 and -2 powers the no-touch exit and the lock.

MP1501 door wiring with everything powered from the board: an HID Wiegand reader on reader port 1 (TB1301), the door contact on input 1 and the no-touch exit on input 2 (TB1400), and the AUX output on TB300 feeding the exit button and a fail-safe maglock through a fuse, relay K1 normally closed (TB1401) and a break-glass. The board runs on PoE through J1000, or on a local 12 V supply on TB300 VIN. MP1501 Field devices AUX 12 V READER PORT 1 · TB1301 TB1301-1 · VO TB1301-2 · LED TB1301-3 · BZR TB1301-4 · CLK / D1 TB1301-5 · DAT / D0 TB1301-6 · GND HID READER · WIEGAND Red · +12 V Orange · green LED Yellow · beeper White · Data 1 Green · Data 0 Black + drain · 0 V INPUTS · TB1400 TB1400-1 · IN1 TB1400-2 · IN1 TB1400-3 · IN2 TB1400-4 · IN2 DOOR CONTACT · DPS COM NC EOL AT CONTACT NO-TOUCH EXIT · REX NO +12 V COM 0 V No-touch exit EOL AT BUTTON POWER · TB300 TB300-1 · VO · AUX 12 V TB300-2 · GND · AUX TB300-3 · VIN 12 V TB300-4 · GND AUX 12 V · EXIT AND LOCK ONLY WITHOUT POE +12 V 0 V Local 12 V PSU RELAYS · TB1401 TB1401-1 · NO TB1401-2 · 1-C TB1401-3 · NC TB1401-4 · NO TB1401-5 · 2-C TB1401-6 · NC K2 · SPARE FUSED +12 V LOCK FEED P1 C P1 NC Break-glass DOUBLE POLE P2 · SPARE + Maglock − 1N4002, CATHODE TO + HOST · J1000 Ethernet · PoE or PoE+ TAMPER · J801 Link, or a tamper switch CLOSED = SECURE TERMINAL STRIP +12 V 0 V +12 V in 0 V in +12 V 0 V ONE FEED IN, SEVERAL OUT POE: 625 mA POE+ OR 12 V: 1.25 A READER INCLUDED FIRE ALARM RELEASE CUTS THIS FEED FUSE +12 V 0 V Contact Optional Lock current Terminal
MP1501 door wiring as a list, with everything powered from the board: each terminal and what it connects to, from the reader port to the maglock. READER PORT 1 · TB1301 → HID READER TB1301-1 · VO Red · +12 V TB1301-2 · LED Orange · green LED TB1301-3 · BZR Yellow · beeper TB1301-4 · D1 White · Data 1 TB1301-5 · D0 Green · Data 0 TB1301-6 · GND Black + drain INPUT 1 · TB1400 → DOOR CONTACT TB1400-1 · IN1 COM TB1400-2 · IN1 NC INPUT 2 · TB1400 → NO-TOUCH EXIT BUTTON POWER: AUX +12 V AND 0 V TB1400-3 · IN2 NO TB1400-4 · IN2 COM AUX OUTPUT · TB300 → EXIT AND LOCK POE 625 mA · POE+ OR 12 V 1.25 A · WITH READER TB300-1 · AUX Exit button +12 V TB300-1 · AUX Fuse, then K1 1-C TB300-2 · GND Exit button 0 V TB300-2 · GND Maglock − LOCAL POWER · TB300 → PSU ONLY WITHOUT POE TB300-3 · VIN PSU +12 V TB300-4 · GND PSU 0 V RELAY K1 · TB1401 → MAGLOCK FAIL-SAFE: POWER RUNS THROUGH NC TB1401-1 · NO not used TB1401-2 · 1-C AUX +12 V, fused TB1401-3 · NC Break-glass P1 C Break-glass P1 NC Maglock + Maglock − TB300-2 · GND IF NEEDED: MOV, OR 1N4002 CATHODE TO + BREAK-GLASS P2: SPARE FIRE RELEASE CUTS THE LOCK FEED TAMPER · J801 Link it, or wire a tamper switch HOST · J1000 Ethernet · PoE or PoE+
The door on an MP1501 with everything powered from the board: a Wiegand HID reader on TB1301, door contact on IN1, exit button on IN2, and a fail-safe maglock fed from the AUX output through relay K1 NC and a break-glass. The dots show data coming in from the reader, and current flowing out of AUX, round the lock and back.

A standard HID pigtail lands like this on reader port 1:

HID wire Signal MP1501 terminal
Red Reader power TB1301-1 · VO
Orange Green LED TB1301-2 · LED
Yellow Beeper TB1301-3 · BZR
White Data 1 TB1301-4 · CLK / D1
Green Data 0 TB1301-5 · DAT / D0
Black, and the drain Ground TB1301-6 · GND
  • Leave the brown (red LED) and blue (hold) wires unconnected unless the reader’s own guide says otherwise. Readers with screw terminals, such as Signo, label them by function: match them the same way.
  • Land the drain on TB1301-6 (GND) at the panel end only.
  • Leave J1202 off for a Wiegand reader. It’s the OSDP terminator for reader port 1.
  • Set the reader port to one-wire LED mode in the host software. In two-wire mode BZR becomes a second LED line and the beeper goes quiet.
  • Use 6-core 18 AWG cable, up to 152 m.

Feed the maglock from AUX through relay K1

A maglock locks while it has power, so it runs through the relay’s normally closed contact. Relay K1 sits de-energised and the lock holds. A valid card energises the relay, NC opens and the door releases.

  1. Feed the relay through a fuse TB300-1 (AUX +12 V), through a fuse sized for the lock, to TB1401-2 (1-C).
  2. Take the lock supply from NC TB1401-3 (NC) to pole 1 of the break-glass, C side.
  3. Through the break-glass to the lock Break-glass pole 1 NC to the maglock +.
  4. Return to the board Maglock − to TB300-2 (AUX GND).
  5. Protect the relay If the maglock has no built-in suppression, fit an MOV or a diode across it, cathode to +. Mercury sizes the diode for the lock’s current and four times its voltage, so a 1N4002 suits 12 and 24 V locks up to 1 A. A diode slows a maglock’s release slightly; an MOV doesn’t.

The no-touch exit also takes its power from TB300-1 and -2, through a small terminal strip beside the board, and its NO and COM contacts go to IN2.

The relay contacts are rated 2 A at 30 V DC, resistive. A lock coil is inductive, one more reason for the suppression. A strike that unlocks with power goes on NO and C instead.

Put the lock on its own battery-backed supply

Here the board runs on PoE and powers only the reader, and a battery-backed 12 V PSU powers the exit button and the lock. The wiring through relay K1 is the same five steps, with the PSU’s +12 V and 0 V in place of TB300-1 and -2.

MP1501 with the exit button and lock on their own supply: the board on PoE through J1000, the no-touch exit on input 2 powered from a battery-backed 12 V PSU, and a fail-safe maglock fed from the PSU through a fuse, relay K1 normally closed and a break-glass. The AUX output is not used. MP1501 Field devices 12 V PSU HOST · J1000 Ethernet · PoE THE BOARD ONLY POWERS THE READER Reader on TB1301 and door contact on IN1: as in the first diagram. INPUT 2 · TB1400 TB1400-3 · IN2 TB1400-4 · IN2 NO-TOUCH EXIT · REX NO +12 V COM 0 V No-touch exit EOL AT BUTTON RELAY K1 · TB1401 TB1401-1 · NO TB1401-2 · 1-C TB1401-3 · NC FUSED +12 V LOCK FEED P1 C P1 NC Break-glass DOUBLE POLE P2 · SPARE + Maglock − 1N4002, CATHODE TO + POWER · TB300 AUX and VIN: not used +12 V 0 V +12 V 0 V BATTERY- BACKED FIRE ALARM RELEASE CUTS THIS FEED FUSE +12 V 0 V Contact Lock current Terminal
MP1501 with the exit button and lock on a battery-backed PSU, as a list: input 2 to the exit button, relay K1 to the maglock, and the board on PoE. HOST · J1000 Ethernet · PoE powers board and reader READER AND DOOR CONTACT: AS ABOVE INPUT 2 · TB1400 → NO-TOUCH EXIT BUTTON POWER: PSU +12 V AND 0 V TB1400-3 · IN2 NO TB1400-4 · IN2 COM RELAY K1 · TB1401 → MAGLOCK FAIL-SAFE: POWER RUNS THROUGH NC TB1401-1 · NO not used TB1401-2 · 1-C PSU +12 V, fused TB1401-3 · NC Break-glass P1 C Break-glass P1 NC Maglock + Maglock − PSU 0 V IF NEEDED: MOV, OR 1N4002 CATHODE TO + THE PSU IS BATTERY-BACKED FIRE RELEASE CUTS THE LOCK FEED POWER · TB300 AUX and VIN: not used
The exit button and maglock on a battery-backed PSU, with the board on PoE. The reader and door contact stay as in the first diagram. The dots show current flowing from the PSU through relay K1 NC and the break-glass, round the lock.
  • Nothing here needs the PSU’s 0 V joined to the board’s GND, because the relay and the exit button’s output are dry contacts. A reader powered from the PSU instead of VO does need its 0 V joined to TB1301-6.
  • A 24 V lock needs this layout, because AUX only gives 12 V. The relay switches up to 30 V DC.
  • Mercury rates the board for power-limited (Class 2) circuits only, so choose a PSU with power-limited outputs.
  • With IN1 and IN2 on the door, the MP1501 has no input left for the PSU’s fault relay.

Let a dead controller release the door

To have a dead MP1501 release a door whose lock has its own supply, wire the lock through NO and set the output to energise-to-lock in the host software, if it supports that. The relay then stays energised all day, and the door stays unlocked whenever the board is down or starting up: about a minute after every power cut, PoE drop or reboot, and longer during a firmware update. The board keeps its settings in flash, so it doesn’t wait for the host. It doesn’t replace the break-glass or the fire release.

Add an exit reader on reader port 2

Reader port 2 takes a second Wiegand or clock-and-data reader, for badging out. It doesn’t do OSDP, and it has no power terminal of its own: its reader runs from the AUX output and counts against the same budget.

HID wire MP1501 terminal
Red TB300-1 · VO (AUX)
Orange TB1300-1 · LED
Yellow TB1300-2 · BZR
White TB1300-3 · CLK / D1
Green TB1300-4 · DAT / D0
Black, and the drain TB300-2 · GND

One line in Mercury’s guide names the AUX output for this reader but gives the terminals as TB1301-1 and -2, which are VO and LED on port 1. That’s a typo: its terminal table and drawings use TB300-1 and -2, which is what the table above follows.

Supervise the door contact and exit button

Each input can be supervised, so the panel reports a cut or shorted cable as well as open and closed. Supervision needs two 1 kΩ 1% resistors at the device end, one in series with the contact and one across it, as close to the contact as you can get them. Run one twisted pair per input, with no more than 30 Ω in the loop. Without resistors, set the input to unsupervised in the host software. It then reports only open or closed. Mercury doesn’t rate them for intruder alarms.

Switch reader port 1 to OSDP

OSDP uses two of the same terminals as Wiegand: TR+ on CLK / D1 (TB1301-4) and TR− on DAT / D0 (TB1301-5). LED and BZR aren’t used, because the reader gets its LED and beeper commands over the data pair. Only reader port 1 does OSDP.

An OSDP reader on MP1501 reader port 1 (TB1301): 12 V from VO, TR+ on CLK/D1 and TR− on DAT/D0 as a shielded twisted pair, and GND, with LED and BZR unused, jumper J1202 on, and an optional second reader on address 1 at the end of the bus. MP1501 OSDP reader Second reader READER PORT 1 · TB1301 TB1301-1 · VO TB1301-2 · LED · not used TB1301-3 · BZR · not used TB1301-4 · TR+ (D1) TB1301-5 · TR− (D0) TB1301-6 · GND ADDRESS 0 +12 V TR+ TR− GND TERMINATOR OFF IF A SECOND READER FOLLOWS SHIELDED TWISTED PAIR ADDRESS 1 · OPTIONAL +12 V TR+ TR− GND END OF BUS: TERMINATOR ON JUMPER J1202 ON · 120 Ω at the panel NEXT TO TB1301 LED 3 The dots: the panel polls each reader in turn, and each one answers. LED 3 on the board flashes every time the panel transmits. POWER VO gives 12 V, up to 600 mA, from the same budget as AUX: 625 mA on PoE, 1.25 A on PoE+ or 12 V. A reader that needs more gets its own supply, with its 0 V joined to GND. CABLE 24 AWG shielded twisted pair, 120 Ω, up to 610 m. Power on its own 18 AWG pair: check its voltage drop on long runs. Drain to GND at the panel only. TWO READERS A second OSDP reader takes the place of reader port 2, which then can’t have a reader of its own. POLARITY No reply? Swap TR+ and TR−. A reversed pair does no harm. +12 V GND TR+ TR− Optional
An OSDP reader on MP1501 reader port 1 as a list: +12 V, TR+, TR− and GND, J1202 on, and an optional second reader on address 1. READER PORT 1 · TB1301 → OSDP READER ADDRESS 0 TB1301-1 · VO +12 V TB1301-2 · LED not used TB1301-3 · BZR not used TB1301-4 · TR+ TR+ TB1301-5 · TR− TR− TB1301-6 · GND GND JUMPER J1202 → ON 120 Ω AT THE PANEL · NEXT TO TB1301 SECOND READER · OPTIONAL ADDRESS 1 · SAME FOUR WIRES FROM READER 1 Reader 1 · +12 V +12 V Reader 1 · TR+ TR+ Reader 1 · TR− TR− Reader 1 · GND GND TERMINATOR ON AT THE LAST READER ONLY READER PORT 2 CAN’T HAVE A READER THEN CABLE Data: 24 AWG shielded twisted pair, 120 Ω, up to 610 m. Drain to GND at the panel only. Power: a separate 18 AWG pair. Check its voltage drop on long runs. VO gives up to 600 mA, shared with AUX.
An OSDP reader on reader port 1, with J1202 on and an optional second reader on address 1 at the end of the bus. The dots show the panel polling each reader in turn and each one answering.
  • Termination: fit J1202, next to TB1301, when the panel is at one end of the bus, and switch on the terminator in the reader at the other end. With two readers, only the last one has its terminator on.
  • The guide contradicts itself here. Its RS-485 notes call the jumper J1201, which is the micro USB port, and one line says not to terminate any device on reader port 1. Revision A.3 added a section saying to close J1202 for OSDP, and the OSDP notes put a terminator at each end of the bus, as above.
  • Two readers at most, on different addresses, for example 0 and 1, at the same baud rate. A second OSDP reader takes the place of reader port 2, which then can’t have a reader of its own.
  • Cable: one 24 AWG shielded twisted pair, 120 Ω, for data, up to 610 m, plus a separate pair for power, 18 AWG like a Wiegand reader’s. On a long run, check the voltage drop on the power pair, or power the reader locally. Land the drain on TB1301-6 (GND) at the panel only. Old Wiegand cores can carry OSDP on short runs, but they may not be twisted pairs, so slow the baud rate down if you reuse them.

Check that the panel polls the OSDP reader

When an OSDP reader doesn’t answer, check the data pair and the reader type in the host software, and watch the board.

  • Swap TR+ and TR− first. Manufacturers disagree on which line is A and which is B, and a reversed pair does no harm.
  • Set the reader type to OSDP in the host software. A reader left on another type, such as “Custom” in Avigilon Unity Access, can show as healthy while the panel isn’t polling it at all.
  • Watch LED 3 on the board. It flashes each time the panel transmits to an RS-485 reader, which confirms the polling.

First power-up

The MP1501 starts on a fixed IP address, and DIP 1 unlocks a default login, so set your own address and account before the host takes over.

  • A new board, or one after a bulk erase, starts on 192.168.0.251, mask 255.255.0.0, gateway 192.168.0.1. The host reaches it on port 3001, communication address 0, with TLS if it’s available.
  • DIP 1 on enables the default login, admin and password, for five minutes. Create your own account straight away. The board reads DIP 1 straight away; the others only at power-up, so reboot after changing them.
  • DIP 4 on makes the board identify itself as an LP1501, for hosts without MP1501 support. Leave it on if your host needs it.
  • Put DIP switches 1 to 3 back to off before you hand the site over.
  • J801 is the cabinet tamper input, and it reads a closed contact as secure. Wire a tamper switch to it: in a wall box, Mercury lists a magnetic switch set for the cover. A wire link works too, but then nothing reports the cover coming off. LED 6 shows the tamper state.
  • Start-up takes about a minute: LEDs 1 to 3 step through their sequence, then LED 4 stays on for 15 seconds once it succeeds. Don’t cut the power while LEDs 1 to 4 flash together, because the board is writing to its flash memory. Once it runs, LED 1 shows the host link: on 20% of the time while off-line, 80% once on-line.

Reset the network settings or wipe the board

Two DIP switch settings, read at power-up, get an MP1501 back to a known state.

  • Factory network settings, nothing erased: power up with DIP 2 on and DIPs 1 and 4 off. The board comes up on 192.168.0.251 without erasing anything.
  • Bulk erase, everything wiped: power up with DIPs 1 and 2 on and 3 and 4 off. When LEDs 1 and 2 start flashing in turn with LEDs 3 and 4, switch DIP 1 off within 10 seconds. LEDs 1 and 4 flash for a few seconds when it’s done, and the board restarts on the default address. Don’t cut the power while it erases.

Afterwards, set DIPs 1 to 3 to off, and DIP 4 the way your host needs it, then reboot so the board reads them.

The terminals, ratings, jumpers, DIP switches and LEDs here come from Mercury’s MP1501 Controller Installation and Specifications (PLT-07669, rev A.3, January 2025), which HID support and Mercury’s partners, such as Keri Systems, publish. Check it against the revision that came with your board. The advice on break-glass, fire release, power loss and troubleshooting is general installer practice, not Mercury’s. HID’s support site is support.hidglobal.com.

Related

GuideWiring a door to a Mercury MP1502