EST-9600 Firmware History

This is the firmware revision log for the EST-9600.

EST-9600 VERSION 2.04 10/06/2021

This release adds the "Raw UDP" operating mode.

The operating mode is selected under "Administration - Operating Mode". When the EST-9600 is configured for "Raw UDP" mode, the device operates similar to an EtherPoll Serial server, except for HDLC synchronous serial data. HDLC frames received on the serial port will be encapsulated in UDP and sent to one or more target destinations. The payload of UDP frames received on the Ethernet port will be sent out the serial port as HDLC frames.


EST-9600 VERSION 2.03 1/11/2021

This release corrects the following:

The "Status - Tunnel Nodes" displayed erroneous values for the "HDLC - Tx Drops" field.


EST-9600 VERSION 2.02 6/5/2020

This release adds the following features:

NTP client support. The feature is located under "Tools - NTP". When enabled, the device will retrieve the time from an NTP server every 4 hours.

Additional HDLC logging. The HDLC driver will log the time when the HDLC controller starts receiving non-empty HDLC frames. Once this happens, the driver will then log the time when it stops receiving HDLC frames for 1 minute. In most applications there should be a continual flow of HDLC packets. If the link fails, the goal is to capture the time that the failure initially occurred. In addition the HDLC driver will log Rx errors using using similar logic. The goal is to capture the time that the link begins to fail.


EST-9600 VERSION 2.01 4/16/2019


This release adds a new mode of operation to the HDLC tunnel. The new mode transports HDCL frames using a NAT friendly, UDP only transport. It is based on the protocol used in our UT products. The advantages of using the new protocol are:

The primary and backup host device may now reside behind the same NAT router, operating on different ports. The older protocol required both primary and backup host to operate on the same TCP/UDP port.

The drop can connect to a primary and a backup residing behind the same NAT router, sharing the same public IP address. The older protocol would not allow the primary and backup to have the same IP address.

The drop device can simultaneously connect to both the primary and backup host, as it did in the older protocol, or it can fail-over from primary to backup in the event that communication to the primary is lost.

Drop devices can reliably operate behind a NAT router. The older protocol used both a TCP and a UDP connection and required the drop to use the same ephemeral port for both connections. NAT routers have the option of remapping ephemeral ports as a means of tracking connections. There is no guarantee that the NAT router would maintain the same ephemeral port for both the TCP and UDP connection.

No open TCP port to be subject to port scanning and denial-of-service attacks.

The new mode of operation is not backward compatible with the old mode of operation. To maintain backward compatible, the user may select the mode of operation when setting up the HDLC Tunnel. The EST-9600 will operate in the older mode, labeled as "Protocol Version v1", by default.

The new mode of operation may be selected from the "HDLC Tunnel" configuration screen by choosing "Protocol Version v2".


EST-9600 VERSION 1.08 5/29/2015


This release adds an HDLC watchdog feature.
When enabled, the watchdog will monitor the HDLC Rx and Tx counters. If either of the counters stop incrementing, for a configured timeout period, the EST-9600 will perform a system reboot. The timeout period may range from 15 seconds to 1 day. Also, the watchdog will hold-off until valid data flow is initially detected.

This feature is in response to the HDLC lockup problem reported by customers using the EST-9600 to carry Motorola Quantar HDLC traffic.


EST-9600 VERSION 1.07 16/1/2011


The "ping" tool did not work correctly This was corrected.


EST-9600 VERSION 1.06 10/12/2009


This release corrects a race condition in the serocco synchronous driver. The race condition would result in the transmitter locking up.


EST-9600 VERSION 1.05 11/16/2007


This release changes the factory self-test.


EST-9600 VERSION 1.03 8/18/2006


The prior version had problems with the key change procedure that happens once the unit is connected to another EST-9600 for 24 hours. Instead of changing keys, it would disconnect and set up a new session. This release fixes that problem.


EST-9600 VERSION 1.02 8/9/2006


The new v1_02 binary for the EST-9600 has these changes:

The Status LED now only has two states: ON or OFF

ON means the software is set up for EXTERNAL CLOCK for HDLC
OFF means the software is set up for INTERNAL CLOCK for HDLC

The Serial driver no longer checks the RLI or carrier detect status before sending frames - it just sends them. If the frames get stuck due to lack of a transmit clock, a software timer later discards all queued output and resets the Serocco transmitter.
One side effect of these changes is that the other HDLC port activity LED can get stuck ON for a few seconds if the TX clock is removed while the port is sending. Just wait a few seconds and it will go out when the transmitter is reset. This is because the LED is extinguished by the timer using the transmit clock.

The other side effect is that when the HDLC port times out, you can read up as to when it happened in the status:HDLC section of the web page.


EST-9600 VERSION 1.01 8/7/2006


Initial public release.

Product was released prior to complete testing due to customer's immediate needs. The firmware is ready for further testing or possible release.

The Status LED works as follows: FLASHING - the unit is not receiving valid HDLC frames on its receive line. This works regardless of whether internal or external clocking is used. If valid HDLC flags are not received on the Serocco RX data line, the LED flashes.

ON - The unit is receiving valid frames and using EXTERNAL CLOCK.
OFF - The unit is receiving valid frames and using INTERNAL CLOCK.

The EXTERNAL/INTERNAL relates the state of the software, not the state of the hardware jumper inside the unit.

Serial Set up

Serial Setup only works when DIP switch 2 is up. When dip SWITCH 2 is down, a message is given that serial setup is disabled.


The unit requires two self tests.

Self Test #1 - Flip switch 3 only UP and reboot.
Self Test #2 - Flip switch 3 and 4 up and reboot.

Test #1 requires connecting to the Ethernet port on via any telnet client. This test prompts the user to use a mux-to-mux cable to test the two serial port signals. It tests the Ethernet, the two serial LEDs and the DIP switch.

Test #2 tests the HDLC port's 4 different modes of operation of RS232/RS485, and also INTERNAL/EXTERNAL clock.


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