{"id":2097,"date":"2021-02-17T02:33:32","date_gmt":"2021-02-17T08:33:32","guid":{"rendered":"https:\/\/scadametrics.com\/blog\/?p=2097"},"modified":"2026-02-12T12:39:55","modified_gmt":"2026-02-12T18:39:55","slug":"introducing-the-smart-bell-202-modem-for-radio-telemetry","status":"publish","type":"post","link":"https:\/\/scadametrics.com\/blog\/?p=2097","title":{"rendered":"Introducing the Smart Bell-202 Modem for Radio Telemetry!"},"content":{"rendered":"
\"James

Jim ‘Slim’ Mimlitz, SCADAmetrics<\/p><\/div>\n\n\n\n

SCADAmetrics\u00ae<\/sup> is pleased to introduce a new member of our DINstrumentation™<\/strong> series \u2013 the Smart Bell 202 Modem<\/strong>! The Model SB.202<\/strong> Modem delivers non-proprietary, Bell-202 data modulation and demodulation for many popular analog telemetry radios. Its rugged design is optimized for use with industrial serial communication protocols, such as
Modbus\/RTU<\/strong>, Allen-Bradley DF1<\/strong>, and DNP3<\/strong>.<\/p>\n\n\n

\n
\"\"<\/a>
‘Smart Bell-202 Modem’. Model SB202.<\/figcaption><\/figure>\n<\/div>\n\n\n

Non-proprietary, Bell-202 modem technology offers significant advantages when applied to certain difficult system integration projects: 1.<\/strong> When combined with licensed VHF and UHF FM radios, it offers unsurpassed ability to punch through dense foliage and communicate across long distances with imperfect line-of-sight. 2.<\/strong> It permits interoperability of a mix of various makes and models of compatible FM radios within a telemetry system.<\/p>\n\n\n\n

In 2012, we introduced a basic, ‘dumb’ Bell-202 modem module for radio telemetry applications. These legacy modems successfully served as drop-in replacements for the popular Calamp DM-3282 modem in the water, wastewater, oil, and natural gas industries throughout the United States, Canada, the Middle East, and Europe for almost a decade.<\/p>\n\n\n

\n
\"\"
Legacy Bell-202 OEM Modem Module.
Model B202.<\/figcaption><\/figure>\n<\/div>\n\n\n

However, the setup of legacy ‘dumb’ modems have traditionally posed challenges to the user. The most demanding tasks are 1. implementation of radio \u201cpush-to-talk\u201d pre-transmit and post-transmit timings; and 2. implementation of a delay in the transmit data stream until a sufficient duration of pre-transmit \u201cpush-to-talk\u201d has completed.<\/p>\n\n\n\n

In the past, push-to-talk timing and transmit data buffering has been achieved by setting up the serial port of the RTU or PLC for hardware flow control, and using the modem\u2019s delayed RTS\/CTS handshake to achieve proper pre-transmit and post-transmit keying of the radio transmitter.<\/p>\n\n\n\n

Sound a little tricky? It used to be \u2014 Until Now<\/strong><\/span>!<\/p>\n\n\n\n

SCADAmetrics\u2019 Model SB.202<\/strong> delivers all the benefits of Bell-202 modem technology \u2013 yet without the hassles. At the heart of the SB.202 is an intelligent microcontroller that supervises the timing of the radio\u2019s transmit data stream, thereby allowing your RTU\/PLC to offload its Modbus requests and responses immediately \u2013 without RTS\/CTS delays. In fact, you may even set up your PLC for simple 3-wire serial communication with RTS\/CTS flow control disabled. The SB.202 then intelligently handles the keying\/unkeying of the radio using dip-switch-selectable timings. It is noteworthy that the Model SB.202 does not <\/em>modify the content of the messages, and it does not<\/em> add proprietary framing layers to the transmissions. Therefore, you may be assured that it will be over-the-air compatible with other-brand modems that adhere to the Bell-202 standard.<\/p>\n\n\n\n

\"\"<\/a>
The Smart Bell-202 Modem \u2013 Front & Back Views.<\/figcaption><\/figure>\n\n\n\n

For example, if your SCADA network\u2019s communication system is built around the Schneider Electric™ SCADAPack 5902 Bell-202 modem and FM radio, then you can be assured that the SB.202 will interoperate seamlessly.<\/p>\n\n\n\n

\n\n\n\n
\"\"<\/a>
The SB.202 is Compatible with the Schneider SCADAPack 5902 Modem.<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n
\"\"<\/a>
SB.202 Modem Installed as a Drop-In Replacement for Schneider 5902 SCADAPack Modem. Note the SCADAPack Model 334 RTU (left) and Motorola XPR2500 VHF\/FM Radio (right).<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n
\"\"<\/a>
The SB.202 is Compatible with Allen Bradley MicroLogix and C*Logix Controllers.<\/figcaption><\/figure>\n\n\n\n
\n\n\n\n

Download PDF Datasheet \/ User Manual Here: Smart Bell-202 Modem<\/a><\/strong><\/p>\n\n\n\n

Are you interested in how SCADAmetrics modem technology can help your SCADA system communicate more effectively through rugged terrain? Give us a call! We\u2019ll be glad to discuss the details!<\/p>\n","protected":false},"excerpt":{"rendered":"

SCADAmetrics\u00ae is pleased to introduce a new member of our DINstrumentation™ series \u2013 the Smart Bell 202 Modem! The Model SB.202 Modem delivers non-proprietary, Bell-202 data modulation and demodulation for many popular analog telemetry radios. Its rugged design is optimized for use with industrial serial communication protocols, such asModbus\/RTU, Allen-Bradley DF1, and DNP3. Non-proprietary, Bell-202 …<\/span> Read More →<\/span><\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":2113,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,125,8,5,6],"tags":[279,280,126,278],"class_list":["post-2097","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applications","category-bell-202-modem","category-general","category-modbusprotocol","category-rockwell-protocols","tag-3-wire-bell-202-modem","tag-automatic-radio-push-to-talk-handling","tag-bell-202-modem","tag-smart-bell-202-modem"],"_links":{"self":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2097","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2097"}],"version-history":[{"count":37,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2097\/revisions"}],"predecessor-version":[{"id":4064,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2097\/revisions\/4064"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=\/wp\/v2\/media\/2113"}],"wp:attachment":[{"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2097"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2097"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/scadametrics.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2097"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}