Sequencing Controller

The RDL RU-SQ6A is a sequencing controller for managing sequential power-up or other timed events. It can coordinate as many as six events, using a front-panel-adjustable interval of 1 to 10 seconds nominal between outputs. Six open-collector outputs and six SPST relay outputs provide two control formats, while front-panel status indication makes each channel’s operating state visible. Sure-Lok™ output supervision is included for sequence oversight.

Ideal Use Cases

This model suits systems in which several power or control events must occur in a defined order rather than simultaneously. It supports sequential ON and OFF functions and can be activated from the front panel or through remote control connections. The six-event capacity is appropriate when a sequence requires up to six controlled steps, and the adjustable timing lets the installer set a common interval for the application. Because both open-collector outputs and contact closures are available, the controller can interface with loads or control inputs that match those published output types and ratings.

Why Choose This Model

The RU-SQ6A combines sequencing, output choices, and visible feedback in one compact unit. Its six relay outputs are SPST contacts that close when active. The six open-collector outputs are rated at 50 mA continuous, with 200 mA surge and a published 200 mA maximum. A bank of ten indicators includes six red channel-on LEDs, a green UP REQUEST LED, a green sequence COMPLETE LED, and red and green indication for remote or front-panel activation. This layout gives the operator direct confirmation of requests, individual active channels, the activation method, and sequence completion.

Installation and Integration

Control and output connections are made at the rear through clearly identified detachable terminal blocks. The control input accepts an external closure drawing less than 2.5 mA at 24 Vdc. The unit requires 24 Vdc at 100 mA, plus the total load current connected to its 24 Vdc output. That output is rated at 1.1 A maximum and 100 mA less than the power supply current. The recommended power supplies, which are not included, are the PS-24AS for the USA and the PS-24AX for international use.

The enclosure measures 1.7 inches high by 5.8 inches long by 3.45 inches deep, or 4.3 by 15.0 by 8.8 cm. Its published ambient operating range is 0°C to 50°C. These details should be checked against the intended location, available DC supply capacity, connected output load, and the electrical ratings of every controlled circuit before integration.

Performance Highlights

The timing interval is nominally adjustable from 1 to 10 seconds at the front panel. Front-panel LEDs show when each output channel turns on and off, and an internal microcontroller provides reliable, accurate timing. For the relay outputs, maximum switching power is 60 W, with the source ratings shown as 220 Vdc, 125 Vac, and 2 A. Maximum switching voltage is 220 Vdc or 250 Vac, maximum switching current is 2 A, and maximum carrying current is 3 A. These limits are distinct and should all be observed when selecting the circuits controlled by the relays.

What Makes It Different

What distinguishes the RU-SQ6A is the combination of up and down sequencing, two output interfaces for a six-event sequence, and comprehensive front-panel feedback. The installer is not limited to relay contacts: open-collector control is also available for compatible interfaces. Likewise, the operator can see an up request, completion state, activation source, and all six channel-on conditions without relying on a separate status display. Sure-Lok output supervision adds a named supervision feature to a controller focused on controlled order and timing.

Final Assessment

For an application needing no more than six sequential events, the RU-SQ6A offers a clearly specified control set: adjustable 1-to-10-second timing, front-panel or remote activation, six SPST closures, six open-collector outputs, and ten LEDs. Its rear detachable terminal blocks support organized installation, while the published DC power, load, relay, physical, and environmental limits provide concrete integration criteria. The required 24 Vdc supply must be selected separately, with PS-24AS and PS-24AX identified as the respective USA and international recommendations.