The 811a Sequence Controller was designed to be a form and functional replacement for aging disk and drum sequencers. It even includes a user interface and RS485 network port.

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                                     811B Time Sequence Controller

 Three cycle counters are supplied, and each can be individually cleared.

The unit includes a complete user interface. There's a rugged operator keypad and a bright display that is visible from twenty feet.

The controller electronically sequences through a series of programmable steps. Each step has a setpoint time that determines how long that step is held. The states of the NO/NC SSR outputs are asserted during each step and can be programmed by the user.


This electronic step sequencer was developed to control time sequenced industrial machinery, such as a tire curing press. The original design of this control was designated as 811A, but a recent redesign now designates the device as 811B. The redesign includes full backwards compatibility with the older 811A device, but now includes an improved user interface that shows more information and also allows the user to select between English or Spanish displays. The 811B includes a rewritten user manual, provided on CDROM in English and Spanish. An 811B Retrofit Upgrade Kit is also available that allows users of aging 811A units to upgrade these controls to the newer 811B design. The Upgrade Kit includes a Quick Start Guide for installation, written in English and Spanish.


The device was designed to be a direct upgrade replacement for older style disk, drum, and electronic sequencers that had been produced by Bristol, Taylor, Tennor, and McNeil but are no longer available. The control is self contained and built into a rugged steel enclosure that fits into the same machine panel cutouts as these older style sequencers. NO/NC pairs of solid state relays are used to provide 120VAC/3.5A outputs for control of the machine's external solenoid valves and loads. These outputs are programmed by the user to be On or Off during any step time.


Other control and handshake signals are provided for interface to a remote machine control system, which can be relay logic or a PLC. Step information can be programmed to allow external devices to extend the time in a step, or remotely end the step currently being run.

Ten different timing sequences of up to 99 steps each with up to 10 hours per step are stored in the system's non-volatile memory. The current operating status of the controller is saved in non-volatile memory when power is lost. The controller is restored to that status when power returns and will then continue from that point in its step program as if nothing happened.


A programmable under cure timer and watchdog timer are included. A keyswitch on the front panel secures access for all step and output programming. Programming can be done at the front panel display and keyboard while the unit is in operation. Various run time information can also be selected for display by pressing buttons on the keypad. The unit includes an opto-coupled RS485 industrial multi-drop network interface to communicate with a remote PC or sequence controllers on the plant floor.