diff --git a/bacnet-stack/demo/mstpcap/readme.txt b/bacnet-stack/demo/mstpcap/readme.txt
index d00b217d..32c07eb8 100644
--- a/bacnet-stack/demo/mstpcap/readme.txt
+++ b/bacnet-stack/demo/mstpcap/readme.txt
@@ -4,7 +4,8 @@ This tool captures MS/TP packets on an RS485 serial interface,
 and saves the packets to a file in Wireshark PCAP format for 
 the MS/TP dissector to read.  The filename has a date and time
 code in it, and will contain up to 65535 packets.  A new file
-will be created at each 65535 packet interval.
+will be created at each 65535 packet interval.  The tool can
+be stopped by using Control-C.
 
 Here is a sample of the tool running (use CTRL-C to quit).
 D:\code\bacnet-stack\bin>mstpcap COM3 38400
@@ -19,15 +20,35 @@ MAC     MaxMstr Tokens  Retries Treply  Tusage  Trpfm   Tder    Tpostpd
 MS/TP capture tool also includes statistics which are listed for
 any MAC addresses found passing a token, 
 or any MAC address replying to a DER message. 
-The statistics are emitted when CTRL-C is pressed, or when
+The statistics are emitted when Control-C is pressed, or when
 65535 packets are captured and the new file is created.
 The statistics are cleared when the new file is created. 
 
-MaxMstr = highest destination MAC during PFM
-Tokens = number of tokens transmitted
-Retries = number of second tokens sent to this MAC
-Treply = max milliseconds it took to reply with a token after receiving a token
-Tusage = max Tusage_delay in milliseconds based on PFM and subsequent token
-Trpfm = max milliseconds to respond to PFM with RPFM.
-Tder = max milliseconds to respond to DER request with DNER
-Tpostpd = max milliseconds to respond to DER request with Reply Postponed.
+MaxMstr = highest destination MAC address during PFM
+
+Tokens = number of tokens transmitted by this MAC address.
+
+Retries = number of second tokens sent to this MAC address.
+
+Treply = maximum number of milliseconds it took to reply with 
+a token after receiving a token. Treply is required to be less 
+than 25ms (but the mstpcap tool may not have that good of 
+resolution on Windows).   
+
+Tusage = the maximum number of milliseconds the
+device waits for a ReplyToPollForMaster or Token retry.
+Tusage is required to be between 20ms and 100ms.  
+
+Trpfm = maximum number of milliseconds to respond to PFM with RPFM.  It is 
+required to be less than 25ms.
+
+Tder = maximum number of milliseconds that a device takes to
+respond to a DataExpectingReply request.  Tder is required to be less
+than 250ms.
+
+Tpostpd = maximum number of milliseconds to respond to 
+DataExpectingReply request with ReplyPostponed.  Tpostpd is 
+required to be less than 250ms.
+Note that the mstpcap tool may not have that good of 
+resolution on Windows, so timing under 50ms may not be accurate.
+