<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0"><channel><title><![CDATA[DLMS Conformance Block Negotiation: Conformance Bits Demystified]]></title><description><![CDATA[<h3>Understanding the 24-bit Conformance Block in AARQ</h3>
<p dir="auto">During Association establishment, the client proposes a set of service capabilities in the <code>Proposed-Conformance</code> bit-string. The meter responds with <code>Negotiated-Conformance</code>, which is the bitwise AND of supported features.</p>
<h4>Conformance Bit Allocations (DLMS Green Book 10th Ed.)</h4>
<pre><code class="language-text">Bit 0:  reserved
Bit 1:  reserved
Bit 2:  read (obsolete)
Bit 3:  write (obsolete)
Bit 4:  unconfirmed-write
Bit 5:  multipurpose-service
Bit 6:  read-access
Bit 7:  write-access
Bit 8:  variable-access-specification
Bit 9:  information-report
Bit 10: reserved
Bit 11: reserved
Bit 12: get (LN)
Bit 13: set (LN)
Bit 14: selective-access
Bit 15: event-notification
Bit 16: action
Bit 17: reserved
Bit 18: block-transfer-with-get
Bit 19: block-transfer-with-set
Bit 20: block-transfer-with-action
Bit 21: multiple-references
Bit 22: information-report-with-data
Bit 23: access-data
</code></pre>
<h4>Standard 24-bit Proposed Conformance for Logical Name (LN) Referencing</h4>
<p dir="auto"><code>00 7E 1F</code> in hex:</p>
<ul>
<li>Enables: <code>GET</code>, <code>SET</code>, <code>ACTION</code>, <code>SELECTIVE-ACCESS</code>, <code>BLOCK-TRANSFER-WITH-GET</code>, <code>BLOCK-TRANSFER-WITH-SET</code>, <code>BLOCK-TRANSFER-WITH-ACTION</code>.</li>
</ul>
<p dir="auto">If your client forgets to set bit 14 (<code>selective-access</code>), any subsequent attempt to read profile buffers by date range will be rejected with <code>Service-Error: service-not-supported</code>!</p>
]]></description><link>https://dlms.sharur.org/topic/16/dlms-conformance-block-negotiation-conformance-bits-demystified</link><generator>RSS for Node</generator><lastBuildDate>Fri, 16 Oct 2026 19:49:49 GMT</lastBuildDate><atom:link href="https://dlms.sharur.org/topic/16.rss" rel="self" type="application/rss+xml"/><pubDate>Sat, 22 Aug 2026 12:33:08 GMT</pubDate><ttl>60</ttl><item><title><![CDATA[Reply to DLMS Conformance Block Negotiation: Conformance Bits Demystified on Sat, 22 Aug 2026 12:36:15 GMT]]></title><description><![CDATA[<p dir="auto">Excellent summary Sarah! A common mistake when writing custom client drivers is hardcoding Short Name (SN) conformance bits (<code>Bit 6: read</code>, <code>Bit 7: write</code>) while attempting to connect to a Logical Name (LN) referencing association. This causes immediate AARQ rejection (<code>result: rejected-permanent, result-source-diagnostic: application-context-name-not-supported</code>).</p>
]]></description><link>https://dlms.sharur.org/post/70</link><guid isPermaLink="true">https://dlms.sharur.org/post/70</guid><dc:creator><![CDATA[david_miller]]></dc:creator><pubDate>Sat, 22 Aug 2026 12:36:15 GMT</pubDate></item></channel></rss>