Buyers compare reader prices and then discover the lock, power supply, exit button and cabling are separate. This page shows you everything a controlled door requires, what it costs installed, and the six mistakes that leave a door failing open in a power cut.
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Lock current assumed at 0.5 A per EM lock and 0.9 A per bolt at 12 V, plus 0.5 A per panel. Batteries sized at 80% usable capacity in 12 V 7 Ah blocks.
The headline product is rarely more than half the installed cost. These are the parts that get left out of budgets.
Fingerprint, face, palm or card. One per direction if you need an exit record.
EM lock (fail-safe) or drop bolt (fail-secure). The choice is a fire-code decision, not a preference.
Load-shedding must not open every door in the building. One per 3–4 doors.
So people can leave. Pressed thousands of times a month — the component that fails first.
Tells the system whether the door actually closed. Without it, door-held-open alarms are impossible.
Reader, lock, button and sensor all cable back to the controller.
Needed when using slave readers. Standalone terminals include it.
Central rules, reports, multi-door. Not needed for a single standalone door.
Often a fire-code requirement on escape doors. Confirm with your fire officer.
The honest trade-offs.
| Consideration | EM Lock | Drop Bolt | Electric Strike | Magnetic Shear |
|---|---|---|---|---|
| Behaviour on power loss | Opens (fail-safe) | Stays locked (fail-secure) | Depends on model | Opens |
| Holding force | 280–600 kg | Moderate | Lower | Highest |
| Fits glass doors | With bracket | Yes | No | With bracket |
| Visible on door | Yes | Mostly hidden | Hidden in frame | Hidden |
| Escape-route legal | Usually yes | Usually no | Check model | Usually yes |
| Best for | Most doors, escape routes | Glass doors, secure stores | Wooden door frames | High-security, concealed |
| Relative cost | Lowest | Moderate | Low | Highest |
Door type and frame material. Wooden, steel, aluminium and frameless glass each need different lock hardware and brackets. Glass in particular is not interchangeable.
Cable routes to every door. Reader, lock, exit button and door sensor all run back to the controller. Through a finished door frame this is difficult and visible.
Power supply position. Central and secure, within cable reach of its doors. Voltage drop over long lock cable runs causes intermittent failures that are very hard to diagnose.
Fire alarm interface. Escape-route doors usually must release on alarm. This must be wired at installation, not added later.
Door closer condition. Access control assumes the door closes on its own. A door that does not close properly generates constant held-open alarms and everyone disables them.
Reader mounting height. 1.2–1.4m for fingerprint. Face terminals need to suit the range of user heights, not a single fixed assumption.
Exit buttons are the wear item. Pressed every time someone leaves — thousands of cycles a month on a busy door. Keep spares; a failed button on a controlled door is a door nobody can leave through.
Batteries in the power supply need replacing every two to three years. A power supply with a dead battery gives no warning until the next outage, when the door behaves unexpectedly.
Cards, if used. In a 300-person site expect 5–10% annual replacement. Biometrics avoid this entirely, which is often the stronger argument for them.
Lock mechanism wear. EM locks have no moving parts and last well. Drop bolts and strikes have moving parts and need servicing at high traffic.
The cost nobody budgets: a system nobody administers. Staff leave and their access stays active. Within two years an unmanaged system has more valid credentials than employees — which is worse than no access control, because you believe you are protected.
Every one has cost a real project real money.
EM locks release on power loss; drop bolts do not. Fitting a drop bolt on an escape route can trap people, and it may be illegal.
Do this: Confirm which doors are escape routes before ordering locks. This is a safety decision.
Lock, power supply, exit button, door sensor and cabling together cost more than the reader on most doors.
Do this: Budget per installed door, not per device. The figures above are complete.
During load-shedding a fail-safe lock opens. Every controlled door in the building unlocks, for hours.
Do this: Battery-backed supply on every door. In Bangladesh this is a requirement.
Entry-only gives arrival times but no departure, so hours cannot be calculated and anti-passback cannot work.
Do this: Decide upfront. Retrofitting exit readers means new cable runs.
Without it the system cannot tell whether the door closed. Held-open detection and forced-entry alarms both become impossible.
Do this: Fit door contacts on every controlled door. They are inexpensive.
Staff depart and their credentials stay active. Within two years there are more valid cards than employees.
Do this: Assign an owner and review the user list monthly. This costs nothing and is the most common real-world failure.
Specifications, models and pricing sit on the product pages.
Rules we apply on every installation. Share this with your installer.
An EM lock opens when power fails; a drop bolt stays locked. On an escape route a fail-secure lock needs a fire-alarm release, and that decision belongs to the fire officer, not the installer.
Measured to the sensor centre. Higher and short staff reach up; lower and the fingerprint angle degrades.
Without one the system cannot tell a door wedged open from a door closed. Most internal breaches are propped doors.
Lock current and data share nothing. A lock on the reader's cable causes resets when the EM lock releases.
A 1N4007 across the lock terminals stops the back-EMF spike that kills reader relays over months.
Put deletion into the HR exit checklist. An active card for a departed employee is the most common audit finding.
Four questions settle almost every access control design. Answer them in this order — answering out of order is how projects get re-quoted.
Read rates fall far enough that staff queue, supervisors prop the door, and the system gets bypassed within a month. Face or card.
Load-shedding releases every fail-safe lock in the building. A system that is open during every outage is not an access control system.
Without a magnetic contact you cannot detect a propped door and cannot distinguish a valid opening from a forced one. It is the cheapest component and it is what makes the door monitored rather than merely locked.
Voltage drop produces a lock that works at commissioning and fails intermittently three months later. It is the hardest fault on this list to diagnose.
Strong backlight defeats face recognition. Check the wall at survey, not after the unit is on it.
No manufacturer warranty, no firmware updates, and no local service path. On a tender with an after-sales obligation this transfers the whole risk to you.
Match the row to your site. Every product listed is one we import, stock and warrant.
Standalone terminals carry their own controller and lock relay, so a single door needs no separate panel.
Every product above is one DigiMark Solution imports, stocks and warrants. Pricing is quotation-based and depends on quantity and configuration — request a quotation or ask on WhatsApp.
What to write into a tender or BOQ so you get comparable quotations instead of five documents you cannot compare.
| Sector | What to specify | Typical scale | The clause bidders exploit |
|---|---|---|---|
| Government / defence | Fail-safe on all escape routes; fire-alarm interface; battery backup stated in hours; authorized-distributor certificate; local service SLA | Per building, often 20–100 doors | Specify the warranty path explicitly or you will be compared against grey-market pricing |
| Garments / manufacturing | Face or card, not fingerprint; IP rating for dusty areas; shift-based access rules; integration with payroll | 500–5,000 users, 5–30 doors | State the environment in the BOQ so bidders cannot substitute fingerprint to win on price |
| Hospital | Fail-safe throughout; infection-control-friendly contactless reading; controlled access to pharmacy and records; 24/7 operation | 10–60 doors | Pharmacy and records rooms are the fail-secure exceptions — list them by name |
| Corporate office | Attendance integration; both-side readers where hours are calculated; visitor handling | 100–1,000 users, 5–25 doors | Decide entry-only versus entry-and-exit before tender, it changes reader count by 100% |
| Bank / financial | Dual control on vault and server rooms; anti-passback; full audit trail retention period stated | 5–30 doors | State the audit-log retention period in months — it drives the software tier |
| School / university | High-throughput at gates; visitor and parent management; tamper-resistant mounting | 1,000–10,000 users | Peak-minute throughput at the main gate is the sizing number, not total students |
A reader or terminal, an electric lock, a battery-backed power supply, an exit button, a door sensor, and cabling back to the controller. The reader is typically about a third of the installed cost. A single fingerprint door usually lands between ৳18,000 and ৳28,000 fully installed.
A fail-safe lock (usually an EM lock) releases when power is lost, so people can escape in a fire. A fail-secure lock (usually a drop bolt) stays locked, protecting a secure area but potentially trapping people. Most escape routes legally require fail-safe. Confirm with your fire officer which doors are escape routes before ordering any locks.
Only if you need an exit record. Entry-only readers halve the reader cost but give you arrival times without departures — so attendance hours cannot be calculated and anti-passback will not work. Decide before installation, because retrofitting exit readers means new cable runs.
Without a battery-backed power supply, every fail-safe lock in the building releases and stays open for the duration of the outage. This is not a minor gap — it is the whole system offline during a predictable, recurring event. Battery backup on every door is a requirement in Bangladesh, not an upgrade.
So the system knows whether the door actually closed. Without a magnetic contact you cannot detect a door propped open, and you cannot distinguish a valid opening from a forced one. They are inexpensive and they are what turns a lock into a monitored door.
One 4-door controller covers four doors. Alternatively, standalone terminals like the ZKTeco F18 include their own controller and relay, so a single door needs no separate panel. Controllers make sense from about four doors upward, where central rules and reporting become worth managing.
Size it for your load-shedding, not a round number. Each EM lock draws about 0.5 A at 12 V and a bolt about 0.9 A; add 0.5 A per panel. The calculator above converts doors and hours into 12 V 7 Ah batteries. For longer outages see our power backup guide.
They control one, two and four doors respectively. The calculator picks the mix that uses the fewest panels — five doors is one C3-400 plus one C3-100, not two C3-400s.
Free site survey across Dhaka and Chattogram. Our engineers confirm the design before anything is quoted.