With the meridian-plugin-protocol-xml-2016.1.6-1.noarch package installed, and the Meridian yum repo set to:

https://packages/branches/release-2017.1.0/rhel$releasever

the upgrade to 2017 fails with:

Resolving Dependencies
--> Running transaction check
---> Package jicmp.x86_64 0:1.4.5-2 will be updated
---> Package jicmp.x86_64 0:2.0.3-1.el7.centos will be an update
---> Package jicmp6.x86_64 0:1.2.4-1 will be updated
---> Package jicmp6.x86_64 0:2.0.2-1.el7.centos will be an update
---> Package jrrd2.x86_64 1:2.0.3-3.el7.centos will be updated
---> Package jrrd2.x86_64 1:2.0.3-4.el7.centos will be an update
---> Package meridian.noarch 0:2016.1.6-1 will be updated
---> Package meridian.noarch 0:2017.1.0-0.20170919.prime54.release.2017.1.0.50 will be an update
---> Package meridian-core.noarch 0:2016.1.6-1 will be updated
--> Processing Dependency: meridian-core = 2016.1.6-1 for package: meridian-plugin-protocol-xml-2016.1.6-1.noarch
--> Processing Dependency: meridian-core = 2016.1.6-1 for package: meridian-plugin-protocol-xml-2016.1.6-1.noarch
---> Package meridian-core.noarch 0:2017.1.0-0.20170919.prime54.release.2017.1.0.50 will be an update
---> Package meridian-plugin-protocol-radius.noarch 0:2016.1.6-1 will be updated
---> Package meridian-plugin-protocol-radius.noarch 0:2017.1.0-0.20170919.prime54.release.2017.1.0.50 will be an update
---> Package meridian-plugin-ticketer-rt.noarch 0:2016.1.6-1 will be updated
---> Package meridian-plugin-ticketer-rt.noarch 0:2017.1.0-0.20170919.prime54.release.2017.1.0.50 will be an update
---> Package meridian-webapp-jetty.noarch 0:2016.1.6-1 will be updated
---> Package meridian-webapp-jetty.noarch 0:2017.1.0-0.20170919.prime54.release.2017.1.0.50 will be an update
---> Package rrdtool.x86_64 0:1.5.5-0.4.el7.centos will be updated
---> Package rrdtool.x86_64 0:1.6.0-0.3.opennms.el7.centos will be an update
---> Package rrdtool-perl.x86_64 0:1.5.5-0.4.el7.centos will be obsoleted
---> Package rrdtool-perl.x86_64 0:1.6.0-0.3.opennms.el7.centos will be obsoleting
--> Finished Dependency Resolution
Error: Package: meridian-plugin-protocol-xml-2016.1.6-1.noarch (@meridian)
Requires: meridian-core = 2016.1.6-1
Removing: meridian-core-2016.1.6-1.noarch (@meridian)
meridian-core = 2016.1.6-1
Updated By: meridian-core-2017.1.0-0.20170919.prime54.release.2017.1.0.50.noarch (meridian)
meridian-core = 2017.1.0-0.20170919.prime54.release.2017.1.0.50
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest

As a workaround, you can stop OpenNMS and run

yum remove meridian-plugin-protocol-xml

before upgrading.