SNAP SSI (Serial Synchronous
Interface) Module
PAGE
1
DATA SHEET
Form 1919-150216
SNAP SSI (Serial Synchronous Interface) Module
Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com
SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com
© 2011–2015 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.
Features
For motion control applications using linear or rotary
transducers
Dual, isolated serial synchronous interface (SSI) inputs
Software configurable
Description
The SNAP-SCM-SSI module provides two individually isolated
serial synchronous interface (SSI) inputs for acquiring data
from linear or rotary transducers used in motion control.
The module can decode both binary and Gray Code, and is
software configurable to set clock speed, frame length, delay
time between data samples, and other parameters.
SNAP SSI modules mount alongside analog, digital, and other
serial modules on any SNAP PAC rack with a SNAP PAC brain
(EB or SB) or R-series controller. The brain or controller
processes the data from the module and can communicate
the data to other parts of an Opto 22 SNAP PAC System™ or to
another system (such as a Modbus® system or an OPC client).
SNAP PAC racks accommodate up to 4, 8, 12, or 16 I/O
modules, with a maximum of 8 serial modules (including SSI
modules) on any one rack. Because the SNAP-SCM-SSI module
is mounted on these standard racks with other SNAP I/O
modules, you can use the combination of analog, digital, and
serial modules required by your application at the location
where they are needed.
NOTE: SSI modules require a SNAP PAC brain (either EB or SB)
or R-series controller with firmware version 8.5c or newer.
These modules do not work with legacy brains or controllers.
Configuration
You use PAC Manager, a free software utility, to configure the
SNAP-SCM-SSI. PAC Manager 9.0 or newer is required.
PAC Manager comes on a CD with every SNAP PAC brain and
controller and is also available for download from the Support
section of our website, www.opto22.com.
To install, configure, and use the SNAP-SCM-SSI, see form
#1931, the SNAP SSI (Serial Synchronous Interface) Module User’s
Guide, available on our website.
How the SNAP-SCM-SSI Samples Data
The SSI module outputs a high clock signal during idle, and it
samples SSI data on falling edges of the clock, starting after
the first rising edge. See the following diagram.
Clock cycle (frame length)
Idle
(inter-frame delay)
Example of data sample with out-of-range error bit
234
1n
n-1
LS
MS
Error
First
sample Second sample Last sample
+Clock
+Data
Part Numbers
Part Description
SNAP-SCM-SSI SNAP 2-Channel Serial Synchronous
Interface Module
SNAP SSI Module
SNAP SSI (Serial Synchronous Interface) Module
SNAP SSI (Serial Synchronous Interface) Module
PAGE
2
DATA SHEET
Form 1919-150216
Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com
SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com
© 2011–2015 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.
Specifications
Pins for Each Port
See diagram on page 3 for location of pin 1.
Use twisted-pair, 24-gauge shielded cable with an additional
pair for common (three pairs total).
For complete installation information, see form #1931, the
SNAP SSI (Serial Synchronous Interface) Module User’s Guide,
available on our website.
Maximum SSI clock frequency 2.5 MHz
Channel-to-channel isolation 1500 VAC
Logic supply voltage 5.0 VDC
Logic supply current 200 mA DC
Compatible I/O processors SNAP PAC R-series controllers and SNAP PAC
EB or SB brains with firmware 8.5c or newer
Number of ports per module 2
Max. number of modules per rack 8
Max. data resolution 24 bits
Maximum cable length 500 feet at 200kHz using twisted-pair, 24-gauge
shielded cable with an additional pair for common
(three pairs total)
Operating temperature -20 to 60 °C
Storage temperature -30 to 85 °C
Torque, hold-down screws 4 in-lb (0.45 N-m)
Torque, connector screws 5.26 in-lb (0.6 N-m)
Agency approvals CE, RoHS, DFARS
Warranty 30 months from date of manufacture
Pin Use
1Clock +
2Clock –
3 Data –
4 Data +
5 Excitation common
SNAP SSI (Serial Synchronous Interface) Module
SNAP SSI (Serial Synchronous Interface) Module DATA SHEET
Form 1919-150216
PAGE
3
Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • www.opto22.com
SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com
© 2011–2015 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.
Dimensions
SNAP-SCM-SSI Serial Synchronous Interface Module
Pin 1 Pin 1
More About Opto 22
www.opto22.com • Opto 22 • 43044 Business Park Drive • Temecula, CA 92590-3614 • Form 1335-131203
SALES 800-321-6786 • 951-695-3000 • FAX 951-695-3095 • sales@opto22.com • SUPPORT 800-835-6786 • 951-695-3080 • FAX 951-695-3017 • support@opto22.com
© 2014 Opto 22. All rights reserved. Dimensions and specifications are subject to change. Brand or product names used herein are trademarks or registered trademarks of their respective companies or organizations.
Products
Opto 22 develops and manufactures reliable, flexible, easy-to-use
hardware and software products for industrial automation,
energy management, remote monitoring, and data acquisition
applications.
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SNAP PAC System
Designed to simplify the typically complex
process of selecting and applying an
automation system, the SNAP PAC
System consists of four integrated
components:
•SNAP PAC controllers
•PAC Projec t™ Software Suite
•SNAP PAC brains
•SNAP I/O™
SNAP PAC Controllers
Programmable automation controllers
(PACs) are multifunctional, modular controllers based on open
standards.
Opto 22 has been manufacturing PACs for over two decades. The
standalone SNAP PAC S-series, the rack-mounted SNAP PAC R-
series, and the software-based SoftPAC™ all handle a wide range
of digital, analog, and serial functions for data collection, remote
monitoring, process control, and discrete and hybrid
manufacturing.
SNAP PACs are based on open Ethernet and Internet Protocol (IP)
standards, so you can build or extend a system easily, without the
expense and limitations of proprietary networks and protocols.
Wired+Wireless™ models are also available.
PAC Project Software Suite
Opto 22’s PAC Project Software Suite provides full-featured, cost-
effective control programming, HMI (human machine interface)
development and runtime, OPC server, and database connectivity
software for your SNAP PAC System.
Control programming includes both easy-to-learn flowcharts and
optional scripting. Commands are in plain English; variables and I/
O point names are fully descriptive.
PAC Project Basic offers control and HMI tools and is free for
download on our website,
www.opto22.com
. PAC Project
Professional, available for separate purchase, adds one SoftPAC,
OptoOPCServer, OptoDataLink, options for controller redundancy
or segmented networking, and support for legacy Opto 22 serial
mistic™
I/O units.
SNAP PAC Brains
While SNAP PAC controllers provide central control and data
distribution, SNAP PAC brains provide distributed intelligence for
I/O processing and communications. Brains offer analog, digital,
and serial functions, including thermocouple linearization; PID
loop control; and optional high-speed digital counting (up to 20
kHz), quadrature counting, TPO, and pulse generation and
measurement.
SNAP I/O
I/O provides the local connection to sensors and equipment.
Opto 22 SNAP I/O offers 1 to 32 points of reliable I/O per module,
depending on the type of module and your
needs. Analog, digital, and serial modules are
all mixed on the same mounting rack and
controlled by the same processor (SNAP PAC
brain or rack-mounted controller).
Quality
Founded in 1974, Opto 22 has established a
worldwide reputation for high-quality products.
All are made in the U.S.A. at our manufacturing
facility in Temecula, California. Because we
test each product twice before it leaves our
factory, rather than only testing a sample
of each batch, we can guarantee most
solid-state relays and optically isolated I/O
modules for life.
Free Product Support
Opto 22’s California-based Product Support Group offers free,
comprehensive technical support for Opto 22 products. Our staff
of support engineers represents decades of training and
experience. Support is available in English and Spanish by phone
or email, Monday–Friday, 7 a.m. to 5 p.m. PST.
Additional support is always available on our website: how-to
videos, OptoKnowledgeBase, self-training guide, troubleshooting
and user’s guides, and OptoForums.
In addition, hands-on training is available for free at our Temecula,
California headquarters, and you can
register online
.
Purchasing Opto 22 Products
Opto 22 products are sold directly and through a worldwide
network of distributors, partners, and system integrators. For
more information, contact Opto 22 headquarters at 800-321-
6786 or 951-695-3000, or visit our website at
www.opto22.com
.
www.opto22.com
