diff --git a/.DS_Store b/.DS_Store
index 1082f48..41b979c 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/piflow/modbusTester.py b/piflow/modbusTester.py
new file mode 100644
index 0000000..8e3e7cf
--- /dev/null
+++ b/piflow/modbusTester.py
@@ -0,0 +1,12 @@
+import minimalmodbus
+
+minimalmodbus.BAUDRATE = 9600
+minimalmodbus.STOPBITS = 1
+
+instrument = minimalmodbus.Instrument('/dev/ttyS0', 1) #device, modbus slave address
+instrument.debug = True
+try:
+    value = instrument.read_float(599) #register -1 for float
+    print("Value: {}".format(value))
+except Exception as e:
+    print("Error: {}".format(e))