diff --git a/ps_simulator.rb b/ps_simulator.rb
index c30d89f..19cbc50 100755
--- a/ps_simulator.rb
+++ b/ps_simulator.rb
@@ -31,6 +31,8 @@ while true
               Telegram.new(telegram_in.object,[42.0].pack("g").bytes.to_a,false)
             when 19 # device class
               Telegram.new(telegram_in.object,[0x00,0x10],false)
+            when 54 # power supply control
+              Telegram.new(0xff,[0x00],false)
             else # error: object not defined
               Telegram.new(0xff,[0x07],false)
           end