ESE ES-185U, Operation And Maintenance Manual

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1.0 INTRODUCTION

The ES-185U is a GPS Master Clock/Time Code Generator. The unit receives accurate time and date information
from Global Positioning System satellites and supplies this data to the user in the form of five (5) different types of
time code (SMPTE/EBU, IRIG-B, ASCII, TC89 and TC90) and a front panel nine-digit display (.56” yellow LEDs).
Two (2) One Pulse Per Second outputs and a GPS “Lock” output are also available. A twelve-channel receiver is
employed that is capable of tracking up to twelve (12) satellites simultaneously, although reception of only one is
required for GPS “Lock”. During normal operation, the GPS “Lock” LED lights when GPS “Lock” is obtained and
goes out when GPS “Lock” is lost. Also, the TTL GPS “Lock” output goes high when GPS “Lock” is obtained and
goes low when GPS “Lock” is lost. If GPS “Lock” is lost, accurate outputs are maintained using internal
temperature compensated crystal oscillators. The Master Control Panel software provided with the unit allows the
user to easily change settings of the ES-185U via a serial port or USB interface. A network interface is provided
with option NTP.

An internal 3V coin cell battery maintains the GPS receiver board memory. If this battery is replaced with a new
coin cell or the coin cell is dead, this will affect how the ES-185U obtains GPS lock from a cold start (i.e. main
power is removed from the unit and the battery backup is off). In this situation, the GPS “Lock” LED will flash until
initial GPS “Lock” is achieved. It will continue to flash for 13 minutes. This timeout period allows the GPS receiver
to acquire the proper data relative to GPS/UTC mode and a satellite almanac. While the GPS “Lock” LED is
flashing, the TTL GPS “Lock” output will alternate between high and low. After the timeout period, during which
the GPS receiver has tracked at least one satellite continuously, the GPS “Lock” LED lights solid to indicate that
the display and outputs have the correct UTC time. The TTL GPS “Lock” output also goes high after the timeout
period has completed.

Several options are available that allow the unit to meet most any requirement of a Master Clock or Time Code
Generator. These options are described in section 8.

IMPORTANT NOTE:

The Antenna Module supplied with the ES-185U is designed for "direct mounting". This implies that the antenna
should be mounted to a "deck plane", which may be a wall, a roof or any other "suitable" surface.

The dome of the Antenna Module is designed for mounting outside (or inside near a window with a view of the
sky) and is capable of withstanding most weather conditions (including sun, wind, rain and snow, etc.). The cable,
however, should be routed so as to minimize its exposure to the elements, especially moisture and direct sun.

In order to prevent moisture from seeping back into the Antenna Module, it is important that the cable "hangs
down" as it exits the Antenna Module. Also, a drip loop should be made between the Antenna Module and the
ES-185U. Improper cable routing may allow moisture to enter the Antenna Module or the ES-185U and
permanently damage the antenna and/or the clock, voiding that portion of the warranty. A recommended
Installation Procedure is provided in section 10.

2.0 INSTALLATION & OPERATION

The basic operation of the ES-185U is nearly as simple as connecting the antenna cable to the clock, applying
power (typically 117 VAC) and allowing the unit to "lock" onto GPS. However, after any "bench" testing is
complete, the most important concern is to mount the Antenna Module and route the cable according to the
instructions provided in section 10.

All other connections between the ES-185U and other equipment should be made by a qualified technician or
engineer. The technician or engineer should be familiar with each piece of equipment being interfaced with the
ES-185U. Please refer to the descriptions and specifications which follow for details concerning the various
Standard Features and Options. Consult the manufacturer of the equipment or the ESE factory if assistance is
required.

3.0 ENCLOSURE

The ES-185U is housed in a 1RU rack-mount enclosure which measures 1 ¾” high x 19" wide x 9 ½” deep (plus
connectors). The ruggedized enclosure is constructed of etched and anodized aluminum. The front panel is black
anodized and the rest of the enclosure is clear anodized. A clear anodized front-panel can optionally be specified.