CYBER SCIENCES STR-100-IRIG-B Satellite Time Reference Installation Guide
- June 12, 2024
- CYBER SCIENCES
Table of Contents
INSTRUCTION BULLETIN
ADDENDUM
Satellite Time Reference
STR-100/IRIG-B
SAFETY PRECAUTIONS
IMPORTANT:
This bulletin supplements the base model STR-100 instruction bulletin,
document no. IB-STR-01. Refer to this document for basic mounting, wiring and
setup.
If the IRIG-B Distribution Module (IDM) is also used, refer to the instruction
bulletin for this device, doc. no. IB-IDM-01.
The Cyber Sciences’ Satellite Time Reference STR-100/IRIG-B accepts a Global
Positioning System (GPS) time signal from a Trimble Acutime 360 GPS smart
antenna and outputs a precision time reference in unmodulated IRIG-B format.
The STR-100/IRIG-B can be distinguished from base model STR-100 units by the
presence of an additional label on the front of the device, which clearly
indicates that the IRIG-B output option is installed. This label is positioned
above the 4-position connector on the front of the STR-100 (the connector
labeled “DCF OUT” on the standard model), and reads “IRIG-B Output Option
Installed”. In addition, the BNC connector on the right side of the STR-100 is
labeled “IRIG-B Out.”
DANGER
HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH
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Only qualifi ed workers should install this equipment. Such work should be performed only after reading this entire set of instructions.
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NEVER work alone.
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Before performing visual inspections, tests, or maintenance on this equipment, disconnect all sources of electric power. Assume that all circuits are live until they have been completely de-energized, tested, and tagged. Pay particular attention to the design of the power system.
Consider all sources of power, including the possibility of backfeeding. -
Apply appropriate personal protective equipment (PPE) and follow safe electrical practices. For example, in the USA, see NFPA 70E.
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Turn off all power supplying the equipment before installing and wiring this device.
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Always use a properly rated voltage sensing device to confi rm that power is off.
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Beware of potential hazards, wear personal protective equipment, and carefully inspect the work area for tools and objects that may have been left inside the equipment.
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The successful operation of this equipment depends upon proper handling, installation, and operation. Neglecting fundamental installation requirements may lead to personal injury as well as damage to electrical equipment or other property.
Failure to follow these instructions will result in death or serious injury.
WIRING
Connectors
With the IRIG-B option installed, two of the STR-100 connectors have new functions:
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The BNC connector used for (modulated) IRIG-B input on the STR100 base model is instead used for (unmodulated) IRIG-B output on the STR-100/IRIG-B.
The output signal level on this interface is TTLcompatible (5Vdc nominal), which is the most common implementation of unmodulated IRIG-B. IRIG-B-compatible devices can be connected directly to this interface according to the drive capabilities listed in the specifications section. -
The four position connector used for DCF77 output on the base model is instead used for distributing the IRIG-B signal at 24Vdc nominal, along with 24Vdc control power, to one or more STR IRIG-B Distribution Modules (STR-IDM). This enables the STR to supply IRIG-B signals to many devices across long distances. The STR-IDM also provides complete electrical isolation at each point of service.
WARNING: The signal levels on this (front) interface are not standard
IRIG-B-compatible. Do not connect any IRIG-B device directly to this interface
as damage to the device may result. This connector uses 24Vdc signal levels
and control power to enable multi-point topology over long distances. This is
connected to one or more STR-IDM devices, which in turn distribute the IRIG-B
signal at the more common 5Vdc nominal.
Direct Wiring of IRIG-B Signal
If only a few IRIG-B devices are being driven then they can be connected
directly to the BNC connector on the side of the STR-100.
The exact number that can be driven depends on the load imposed by each device
and the cable type and distance. The cable employed can be 75 ohm coaxial
cable or twisted pair cable provided the correct BNC to twisted pair adapter
is used. This configuration is shown below.
GPS system architecture showing STR-100/IRIG-B with
direct IRIG-B time sync output signal
Multi-point Wiring of IRIG-B Signal
The optional STR-IDM allows multi-point wiring of the IRIG-B signal as
shown below. Typically, IRIG-B signals must be wired point-topoint.
The IDM greatly simplifies wiring of IRIG-B devices by allowing distribution
of the IRIG-B time signal over multi-point communications and across longer
distances.
GPS system architecture
showing STR-100/IRIG-B with multi-point distribution of IRIG-B time sync
signals using the IDM
STR-100/IRIG-B Multi-point Output
Each STR-IDM has two identical 4 position connectors making it easy to daisy-
chain connections to multiple STR-IDMs from the STR-100.
The STR-IDM output connectors are defined as follows. The colors suggested are
for Belden 8770 cable.STR-100/IRIG-B Multi-point
IRIG-B Output Connections
WIRING (continued)
STR-IDM Wiring
Each STR-IDM has two identical 4 position connectors making it easy to daisy-chain connections to multiple STR-IDMs from the STR-100.
The multi-point IRIG-B input wiring for the STR-IDM is shown below.
Refer to the IDM instruction bulletin (document number IB-IDM-01) for complete information.
SETUP
Note: Most setup options are the same as those of the base model STR-100 and
are described in IB-STR-01.
However, one item is unique to the STR100/IRIG-B and MUST be changed for
proper operation: > 8: Acutime > 5: Set Satellite Threshold.
The STR-100/IRIG-B provides a terminal interface for confi guration, very
similar to the base model STR-100 and described in detail in the STR-100
instruction bulletin (IB-STR-01). The STR user interface is accessed by
connecting a PC running HyperTerminal (or equivalent).
Using a null modem cable, connect a PC to the STR COM 1 serial port, and confi
gure HyperTerminal for 19200bps, 8 bits, no parity, 1 stop bit.
When the STR is powered ON or when the unit is RESET, the terminal interface
begins execution and runs continually from that point. If a PC running
HyperTerminal is properly connected, the prompt “Press ENTER to activate
terminal interface.” is displayed on the PC screen.
Even if the prompt does not appear, pressing ENTER will bring up the main
menu. To exit the terminal interface at any time, press ESC. The terminal
interface can be restarted at anytime by pressing ENTER.
The STR-100/IRIG-B main menu displays the STR fi rmware version number, date,
and time on the top line along with the status of GPS source. The data
presented on the top line does not automatically update. The actions available
to the user are listed along with a selection number. Enter the desired number
at the “Selection:” prompt and press ENTER. Pressing ENTER without making a
selection will refresh the screen with updated values on the top line of the
main menu. Pressing ESC will deactivate the terminal interface until ENTER is
pressed again.
SETUP (continued)
While most STR-100/IRIG-B setup choices are optional, one change to the
default settings of the Acutime 360 antenna is required to ensure proper
IRIG-B output and reliable interoperability with some IRIG-B devices.
The STR-100/IRIG-B main menu is shown below:
Main Menu
8—Acutime
This item displays the Acutime GPS antenna main menu, used to view or set
the antenna parameters. These menu options allow the user to configure the
antenna parameters via the STR. The first four (4) items are optional, and
more details are provided in the main STR-100 instruction bulletin.
The fifth item, Set Satellite Threshold, must be changed for proper operation
with IRIG-B devices, as described in the next section.
8—Acutime (continued)
The Set Satellite Threshold screen allows the user to set the minimum
number of usable satellites required to initiate or maintain the GPS antenna’s
PPS (pulse per second) signal to the STR-100/IRIG-B. The default value is 3,
but this setting must be changed to 0 for proper operation.
OPERATION
During normal operation, the green LEDs marked PWR and SYNC remain on steady. The LED marked IRIG-B will appear to “flicker” at a high rate confirming IRIG-B data is being output. This is normal and reflects the high pulse rate (1 kHz) of the IRIG-B signal.
TECHNICAL SPECIFICATIONS
SPECIFICATIONS|
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Unmodulated IRIG-B output| The IRIG-B output conforms to IRIG-B (type B007):
• Format B, 100 PPS (pulses-per-second)
• 0 = unmodulated (DC level shift, pulse-width coded)
• 0 = no carrier
• 7 = BCD coded expressions (time of year, year), SBS
Direct IRIG-B output (BNC on side)| TTL-level signals (5Vdc nominal):
Vlow (max. voltage for logical “0”) = 0.4 volts @ 24 mA
Vhigh (min. voltage for logical “1”) = 3.2 volts @ -15 mA
Multi-point IRIG-B output (front)| 24Vdc nominal signals + 24Vdc control power
(for distribution to STR-IDM)
Power requirements| 24 Vdc (nominal), sourced by a class 2 rated supply.
Burden of 36 watts max, depending on output loading.
Typical no-load power consumption is 4 watts.
Doc. no: IB-STR-02R2
Jan-2022 (supersedes doc. dated Jul-2011)
Cyber Sciences, Inc. USA
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Documents / Resources
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CYBER SCIENCES STR-100-IRIG-B Satellite Time
Reference
[pdf] Installation Guide
STR-100-IRIG-B Satellite Time Reference, STR-100-IRIG-B, Satellite Time
Reference, Time Reference
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