diff --git a/libnymea-modbus/tools/README.md b/libnymea-modbus/tools/README.md
index d2387d0..4ac0c0a 100644
--- a/libnymea-modbus/tools/README.md
+++ b/libnymea-modbus/tools/README.md
@@ -127,7 +127,7 @@ Depending on your device the amount of errors in a row can vary and can be speci
 
 In order to check if the device is reachable, a register can be defined by the developer as a test register.
 For this purpose the `checkReachableRegister` property has been introduced. The property describes the `id` of the register which will be used for testing the communication. The register should be mandatory on the device
-and only one register in size to speed up things. During the check the response data will be ignored, only the communication will be tested. The register must be *readable* and be defined in the `registers` section of your JSON file.
+and only one register in size to speed up things. During the check the response data will be ignored, only the communication will be tested. The register must be *readable* and be defined in the `registers` section of your JSON file or in a block.
 
 ## Endianness
 
diff --git a/libnymea-modbus/tools/generate-connection.py b/libnymea-modbus/tools/generate-connection.py
index b402923..257cd89 100644
--- a/libnymea-modbus/tools/generate-connection.py
+++ b/libnymea-modbus/tools/generate-connection.py
@@ -758,6 +758,18 @@ for registerDefinition in registerJson['registers']:
         registerExists = True
         break
 
+if 'blocks' in registerJson:
+    for blockDefinition in registerJson['blocks']:
+        for registerDefinition in blockDefinition['registers']:
+            if registerDefinition['id'] == checkReachableRegister:
+                if not 'R' in registerDefinition['access']:
+                    logger.warning('Error: The specified \"checkReachableRegister\" is not readable. Please select a manadtory readable register as checkReachableRegister.')
+                    exit(1)
+
+                checkReachableRegister = registerDefinition
+                registerExists = True
+                break
+
 if not registerExists:
     logger.warning('Error: Could not find the given \"checkReachableRegister\". Please make sure the specified register matches the \"id\" of a defined register.')
     exit(1)