diff --git a/write_log_serial.py b/write_log_serial.py
new file mode 100755
index 0000000..79443c9
--- /dev/null
+++ b/write_log_serial.py
@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+
+# Based on Morningstar documentation here
+# http://www.morningstarcorp.com/wp-content/uploads/2014/02/TSMPPT.APP_.Modbus.EN_.10.2.pdf
+# and heavily modified version of the script here
+# http://www.fieldlines.com/index.php?topic=147639.0
+
+# This is modified for the non-MPPT tri-stars without built-in network monitoring. It has different indices and different available data.
+
+import sys
+import re
+import time
+
+# import the server implementation
+from pymodbus.client.sync import ModbusSerialClient as ModbusClient
+
+# configure the client logging
+import logging
+logging.basicConfig()
+log = logging.getLogger('./modbus.error')
+log.setLevel(logging.ERROR)
+
+client = ModbusClient(method='rtu',port='/dev/ttyUSB0', baudrate=9600, timeout=1)
+client.connect()
+log.debug(client)
+
+# Define the State list
+state = ['Start', 'Night Check', 'Disconnected', 'Night', 'Fault!', 'BulkCharge', 'Absorption', 'FloatCharge', 'Equalizing']
+
+# read registers. Start at 0 for convenience
+rr = client.read_holding_registers(0,37,1)
+if rr == None:
+    client.close()
+    log.error("couldn't connect")
+    exit(1)
+
+# for all indexes, subtract 1 from what's in the manual
+v_scale = 96.667 * 2**(-15)
+i_scale = 66.667 * 2**(-15)
+array_scale = 139.15 * 2**(-15)
+
+# battery terminal voltage
+battsV = rr.registers[8] * v_scale
+
+# load current
+# battsI = rr.registers[12] * i_scale * 4.75
+
+# array voltage
+arrayV = rr.registers[10] * array_scale
+
+# charge current
+arrayI = rr.registers[11] * i_scale
+
+# charge state
+statenum = rr.registers[27]
+
+# heat sink temperature
+hsTemp = rr.registers[14] 
+
+# configuration dipswitches
+dipswitches = bin(rr.registers[25])[::-1][:-2].zfill(8)
+
+print "%s vB: %.2f\tvP: %.2f\tcC: %.2f\t P: %.2f\tS: %s" % (time.strftime("%Y-%m-%dT%H%M%S%Z"), battsV, arrayV, arrayI, battsV*arrayI, state[statenum]) 
+client.close()