Overview
MAXSYS access control kits bundle PC4820 door control, PC4850 card access, readers, credentials, and related Combus modules for PC4020-based integrated intrusion + access installs. Access shares the same panel, partitions, user codes (up to 1,500), and 64 access levels as burglary—doors can be shunted, scheduled, and reported through the same communicator.
End-user benefits highlighted in DSC's MAXSYS end-user guide:
- Seamless integration — One system monitors who enters and when, tied to intrusion partitions.
- Simple operation — LCD keypads with programmable function keys; one-button arming shortcuts.
- Rugged reliability — Industry-leading lightning and static protection on MAXSYS panels.
- False alarm reduction — Panel features reduce nuisance alarms on commercial sites.
- IP reporting — T-Link TL-250/TL-300 uses existing LAN paths with AES encryption options.
Typical targets: middle-market retailers, schools, government buildings, industrial complexes, financial institutions, and high-end multi-unit residential.
At a Glance
| Component | Role |
|---|---|
| PC4020 host | Intrusion + access logic, Combus, communicator |
| PC4820 | Door control modules (up to 16 on system) |
| PC4850 | Card access control modules (up to 16) |
| User codes | 1,500 codes; assign to access levels and partitions |
| Automation | PC4401 DataLink optional for building automation tie-in |
Before You Deploy a Kit
- Confirm door count, reader type, and fail-safe vs fail-secure hardware per door.
- Plan Combus addresses for PC4820/PC4850 alongside zone and output modules.
- Program access levels, time zones, and anti-passback rules in DLS—not at the keypad alone.
- Verify fire release and unlock on AC loss requirements with local code.
Official Sources
- Product page: DSC MAXSYS Access Control Kit (ID 24)
- 30-214 MAXSYS End-user Cheat Sheet; MAXSYS 12-page brochure — DSC official documentation
- PC4020 v3.5 Installation Manual and PC4820/PC4850 module install sheets
Error Codes
Access control faults appear as PC4020 system troubles and door/module status—there is no separate access-kit trouble code list.
Access-Related Host Troubles
| Condition | Display / behavior | First checks |
|---|---|---|
| Door forced / held | Burglary zone or access event | Door contact, strike wiring, schedule |
| PC4820 comms loss | Diagnostics E on module # | Combus wire, enrollment, power |
| PC4820 tamper | Diagnostics T | Reader/panel tamper loop |
| PC4820 low voltage | Diagnostics LV | Combus repower, wire length |
| Access denied at reader | No trouble—user event | Access level, schedule, code expired |
| FTC on access event | Communicator trouble | Reporting path separate from door hardware |
User-Facing Messages
Consult the 30-214 MAXSYS End-user Cheat Sheet for simplified end-user messaging. Installers should use DLS event log for access granted/denied, door forced, and communicator detail.
Source: MAXSYS end-user documentation; PC4020 Installation Manual §16.
| Code | Meaning | Suggested Fix |
|---|---|---|
| Condition | Display / behavior | First checks |
| Door forced / held | Burglary zone or access event | Door contact, strike wiring, schedule |
| PC4820 comms loss | Diagnostics E on module # | Combus wire, enrollment, power |
| PC4820 tamper | Diagnostics T | Reader/panel tamper loop |
| PC4820 low voltage | Diagnostics LV | Combus repower, wire length |
| Access denied at reader | No trouble—user event | Access level, schedule, code expired |
| FTC on access event | Communicator trouble | Reporting path separate from door hardware |