diff --git a/config/devices.properties b/config/devices.properties
index 2c8e353..cdf44b6 100644
--- a/config/devices.properties
+++ b/config/devices.properties
@@ -1,4 +1,4 @@
 robot=RobotTcp|127.0.0.1:1000|||
-robot_modbus=RobotModbus|129.129.110.99|||
+robot_modbus=RobotModbus|129.129.110.99:520|||
 $dewar=ch.psi.pshell.modbus.ModbusTCP|127.0.0.1|||
 $temperature=ch.psi.pshell.modbus.AnalogInput|dewar 0|||