Industrologic OC16SPI

SPI Interface 16 Channel Relay/Lamp/LED Driver Board

Reference Manual

version 8/14/18

Industrologic, Inc.
3201 Highgate Lane
St. Charles, MO

(636) 723-4000

Trademark and Copyright Information

OC16SPI is a Trademark of Industrologic, Inc. 2018

This document is Copyright (c) 2018 by Industrologic, Inc.
All rights reserved.

No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying or scanning, for any purpose other than the personal use by the purchaser of this product. Industrologic, Inc. reserves the right to revise this document at any time without obligation to notify any person of such revision. Industrologic, Inc. assumes no responsibility for any errors that may appear in this document.

The software distributed with and the firmware contained in this product is Copyright (c) 2018 by Industrologic, Inc.


Whereas effort has been made to make the information in this document as useful and accurate as possible, Industrologic, Inc. assumes no responsibility for the application, usefulness, or completeness, of the information contained herein. Under no circumstance will Industrologic, Inc. be responsible or liable for any damages or losses including indirect or consequential damages or losses arising from either the use of any information contained within this manual or the use of any products or services referenced within this manual.

Industrologic, Inc. reserves the right to change any product's features, specifications, documentation, warranties, fee schedules, and conditions at any time and without notice.

Industrologic products are provided as printed circuit board level assemblies. Some Industrologic products may include mechanical packaging accessories which are provide for the purchaser's convenience, and are not intended to be final assembly enclosures.

Industrologic products are provided with the understanding that the purchaser will determine fitness for any particular application as well as achieve compliance with any particular specifications or regulations as required or desired for that application.


Industrologic, Inc. products are warranted to be free from defects in workmanship or material under normal use and service for a period of one year from date of purchase. Industrologic's warranty is to the original purchaser only, but is extended to you by the Distributor or OEM from whom you purchased the product.

Industrologic's obligation under this Warranty is limited to replacement with a new or repaired unit to the original purchaser. The unit must be returned, and replacements obtained from Industrologic, Inc. or the Distributor or OEM from whom it was purchased.

This warranty will not apply if, in the judgment of Industrologic, Inc., damage or failure of the product has resulted from accident, alteration, misuse, abuse, connection to or operation with incompatible signals or power sources, or improper installation.

Under no circumstances shall Industrologic, Inc. be liable to purchaser or any third party for any loss of profits or other direct or indirect costs, expenses, losses, or consequential damages arising out of or as a result of any defects in or failure of Industrologic products or any part or parts thereof.


Return and Repair Policy

Products purchased in single piece quantities may be returned, if in resellable condition, for a full refund of the purchase price only, to the original purchaser, within 30 days of purchase.

Products must be returned by original purchaser with a Return Materials Authorization (RMA) number issued by Industrologic, Inc. or the Distributor or OEM from whom it was purchased, authorizing its return. Current repair or replacement fees and procedures will be related during the issue of the RMA number.

Warranty or repair units must be returned with postage and insurance paid by purchaser. Industrologic, Inc. is not responsible for damages or loss during shipment.

Industrologic OC16SPI

SPI Interface 16 Channel Relay/Lamp/LED Driver Board

The Industrologic OC16SPI is a printed circuit board assembly designed to provide 16 medium current relay coil/lamp/LED drivers to microcontroller boards via a Serial Peripheral Interface (SPI) style interface. The OC16SPI includes 16 open-collector NPN transistor drivers (with back-EMF diodes for relays) and connections for each relay coil/lamp/LED available on screw terminable block connections. The OC16SPI is available as a complete circuit board assembly with convenient screw terminal block connections, and can be enclosed in an optional ABS plastic enclosure, alone or with an RC51 or SI51.

picture of OC16SPI

Electrical Specifications

Operating environment:
Temperature: 0-50 degrees Celsius (32-122 Fahrenheit)
Humidity: 30 to 80 percent, non-condensing

Power supply requirements-
Voltage matching the relay coil/lamp/LED voltage at the +V connection
5 volts DC regulated, 25 mA at the +5 volt connection

SPI control signals-
5 volt logic levels
Relay/lamp/LED driver outputs-
48 volts maximum
500 mA (dependant on number of outputs conducting and temperature)

Mechanical Specifications

.062" FR-4 glass epoxy printed circuit board, 6.25 inches by 3.50 inches.
P.C. Board assembly has holes available for mounting to enclosure or #6 standoffs.
Same form-factor as Industrologic SI51 and RC51.
(May be installed with an SI51 or RC51 in their case.)

OC16SPI dimensions and connections

Powering the OC16SPI

The logic circuits on the OC16SPI are powered by connecting +5 volts and ground to the +5 and ground connections at the screw terminal blocks. Power for the relay coils/lamps/LEDs is connected to the +V and ground connections at the screw terminal blocks. If the relays, lamps, or LEDs used are 5 volts, then the +5 and +V connections can be the same, as long as sufficient current is available for the relays, lamps, or LEDs.

Connecting Devices to the Drivers

Relay coils, lamps, and LEDs can be connected to the OC16SPI drivers by connecting these devices from +V to the individual outputs. The outputs "sink" the current to ground, thereby turning on the device. If LEDs are used, they must include current limiting resistors.

SPI Control Signals

The OC16SPI is based on two 4094 (e.g. CD4094, 74HC4094) 8 stage shift and store bus register and latch chips. The control signals STROBE, DATA, and CLOCK work in a similar (but not identical) manner as SPI interface devices.

You cannot just connect the OC16SPI to the SPI interface of a microcontroller system and expect it to work. There are variations in the SPI protocol that will require research into the protocol needed to operate the OC16SPI.

Note: The digital input/output signals of many Industrologic products have small filter capacitors connected from the signal to ground for protection of the microcontroller pins. If the OC16SPI control signals will be driven by such signals, the capacitors will need to be removed.

Using Multiple OC16SPI Boards

When connecting multiple OC16SPI boards to digital output signals, the DATA and CLOCK signals from all of the boards may be connected together. The STROBE signal of each board must be connected to a separate digital output signal in order to control those boards independantly.

Using the Control Signals to Turn the Drivers On and Off

On the OC16SPI the output latch part of the 4094 chips is disabled for about 1 second with a hardware timing circuit when power is first applied to the board. This insures that all of the drivers are initially off during that period, and gives the device that is controlling the OC16SPI time to initialize its I/O signals to their preferred state, and to initialize the shift register portion of the chips (usually with all outputs off) before enabling the output latch. If this initialization is not done, one or more of the OC16SPI outputs may be on.

For a detailed explanation of the sequence used to operate the 4094 chips you may elect to refer to a datasheet for the chip, however, for many people, the following sequence of changes in the control signals will be easier to understand and to incorporate into a microcontroller program.

If the OC16SPI is being controlled with I/O signals from a fast microcontroller or logic circuit, time delays may be necessary at the indicated places below.


1. Power up the OC16SPI
2. Set STROBE, DATA, and CLOCK "low" while output register is disabled by the hardware.
Optional delay

Setting the outputs on/off:

1. Set DATA high or low to turn Output 9 on or off.
Optional delay
Set CLOCK "high"
Optional delay
Set CLOCK "low"
Optional delay
2. Repeat step 1 for Output 10
3. Repeat step 1 for Output 11
4. Repeat step 1 for Output 12
5. Repeat step 1 for Output 13
6. Repeat step 1 for Output 14
7. Repeat step 1 for Output 15
8. Repeat step 1 for Output 16

9. Repeat step 1 for Output 1
10. Repeat step 1 for Output 2
11. Repeat step 1 for Output 3
12. Repeat step 1 for Output 4
13. Repeat step 1 for Output 5
14. Repeat step 1 for Output 6
15. Repeat step 1 for Output 7
16. Repeat step 1 for Output 8

17. Set STROBE "high"
Optional delay

18. Set STROBE "low"
After this step the relays will be set to the values used on the DATA signal.
Optional delay

19. Set DATA "low"
This optional step returns the DATA signal to its original "low" state.

OC16SPI Schematic Diagram

OC16SPI schematic diagram

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