DATA SHEET
SNAP Serial Communication Modules
Form 1184-150212
SNAP Serial
Communication Modules
Features
SNAP-SCM-232: Two RS-232 serial ports with optional
RTS/CTS flow control
SNAP-SCM-485-422: Two RS-485 2-wire serial ports or
one RS-485/422 4-wire serial port
SNAP Serial Communication Modules
Individually isolated ports
Baud rates to 115 K Baud
beside digital and analog modules, to provide the mix of
analog, digital, and serial channels you need at any location.
Connection accessories provided
Works with the SNAP PAC System
Typical applications include interfacing with printers, scales,
chart recorders, and barcode systems. Using the SNAP-SCM-
Up to eight serial modules per rack
232 or SNAP-SCM-485-422 as a converter, these non-Ethernet
30-month warranty
devices can be connected to an Ethernet network and be
available for control, monitoring, or data acquisition by any
authorized PC or other device on the network.
Description
With the SNAP-SCM-232, two short (12-inch), unshielded
The SNAP-SCM-232 and SNAP-SCM-485-422 serial
twisted-pair cables and two DB9 (male) adapters are included
communication modules are part of the SNAP PAC System.
for easy connection to all types of RS-232 devices.
They conveniently provide two channels of serial data at a
SNAP racks use a retention rail locking system that holds
remote Ethernet location.
modules securely to the rack. Normally, a hold-down screw is
Many applications require digital, analog, and serial data to
not required. However, for applications that require additional
provide a complete solution. Traditionally, either separate
module security, each module has provisions for two 4-40 by
serial network cabling is required for the serial devices, or an
-inch standard machine screws to hold each module in
expensive data processor or PC must be used just to interface
position on the SNAP rack.
with the serial devices.
For details on using these modules, see Opto 22 form #1191,
SNAP serial communication modules eliminate this problem
the SNAP Serial Communication Module Users Guide.
by providing two channels of high-speed, isolated serial
Notes for legacy hardware: These SNAP serial
communications packaged in the compact SNAP module
communication modules can also be used with SNAP Simple,
form.
SNAP Ethernet, and SNAP Ultimate brains on an M-series or B-
The SNAP-SCM-232 interfaces to auxiliary serial
series rack. SNAP-SCM-232 modules offering RTS/CTS flow
equipment via two RJ-45 plug-in data connectors,
control were manufactured in June 2003 or more recently and
providing two RS-232 serial ports. The module also
require I/O processor firmware version 5.0 or newer. The SNAP-
supports optional RTS/CTS flow control.
SCM-485-422 also requires firmware 5.0 or newer. An older
The SNAP-SCM-485-422 uses the standard SNAP
module part number, SNAP-SCM-485, supported 2-wire RS-
removable top-mounted connector for easy wiring of
485 only.
two 2-wire RS-485 ports or one 4-wire RS-485/422 port.
The module has convenient top switches for termination
and bias.
Part Numbers
LED indicators are provided on each module to indicate
Part Description
Transmit and Receive on each port.
Two-channel RS-232 serial
Both SNAP serial communication modules work with SNAP
SNAP-SCM-232
communication module
PAC Ethernet-based brains and rack-mounted controllers,
both standard wired models and Wired+Wireless models. Two-channel RS-485 (two-wire) or
SNAP-SCM-485-422 single-channel RS-485/422 (four-wire)
(They do not work with serial-based SNAP PAC brains.) These
serial communication module
modules snap into Opto 22 SNAP PAC mounting racks right
Opto 22 43044 Business Park Drive Temecula, CA 92590-3614 www.opto22.com
PAGE
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
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20062015 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.SNAP Serial Communication Modules
Specifications
Baud rates 300115,200*
LED Indicates
750 V
Channel-to-channel isolation
RMS
1 TX port A
Logic supply voltage 5.0 VDC
2 TX port B
Logic supply current 250 mA DC
3RX port A
Number of ports per module 2 (1 if SNAP-SCM-485-422 in 4-wire mode)
4RX port B
Max. number of modules per
8
rack**
Maximum cable length, point-to-
50 feet
point (SNAP-SCM-232)
Maximum cable length, multidrop
1,000 feet at 115,200 Kbd
(SNAP-SCM-485-422)
SNAP PAC R-series controllers and SNAP
PAC EB brains, both standard wired and
Wired+Wireless models.
Processor compatibility
Also SNAP-B3000-ENET, SNAP-ENET-RTC,
SNAP-ENET-S64, SNAP-UP1-ADS, and
SNAP-UP1-M64.
Operating temperature -20 to 70 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, FM, RoHS, DFARS
Warranty 30 months
* Module performance is limited by the number of serial modules on the SNAP
rack. Each rack backplane provides approximately 2.5 Mbps of bandwidth.
** Maximum number of modules per rack assumes an Opto 22 SNAP power sup-
ply and SNAP rack.
Opto 22 43044 Business Park Drive Temecula, CA 92590-3614 www.opto22.com
PAGE
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
2
20062015 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.
DATA SHEET
SNAP Serial Communication Modules
Form 1184-150212