diff --git a/doc/erko_howto_tools.txt b/doc/erko_howto_tools.txt
index 331c88ad51e35af98694cc004c3bb75a84cc4a16..4146bec45c38f9d6b98fb7bbdf4bb8d3183ffb00 100755
--- a/doc/erko_howto_tools.txt
+++ b/doc/erko_howto_tools.txt
@@ -835,6 +835,8 @@ Works from home in VPN:
 * LTS --> http://test-lcu2.astron.nl:8888/notebooks/   # = dop81
 * DTS --> http://dts-lcu.astron.nl:8888/notebooks/
 
+Check of SDPTR op dop369 actief is met:
+> uals -u 10.87.2.36:4840 -p "0:Objects"
 
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 * Zenodo DOI