Tekron International - Frequently Asked Questions
Frequently Asked Questions
If you can't find the answer to your question here, please email us with your query.
What is IRIG-B?
- IRIG-B is a time code that has 2 common forms: Amplitude Modulated (AM) (IRIG-B12x) or Unmodulated (DC or Digital) (IRIG-B00x)
- Both IRIG-B forms have 100 coding elements per second which build up the time message over each second
- AM IRIG-B has historically been used but is less accurate and is being phased out in favour of DC IRIG-B is now becoming the generally accepted time code standard
- DC IRIG-B can easily be transmitted over fibre optic links
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Why are isolated outputs important?
- Voltage spikes can be induced on control cabling during fault conditions
- Isolated outputs reduce the risk of time sync signal corruption due to the voltage spikes during fault conditions — precisely when accurate timing is vital
- Isolated outputs reduce the safety risk and the risk of damage to equipment from voltage spikes through the time sync cabling
- For more detailed information on isolation click here
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What are MOFRs?
- MOFRs are Multi Output Function Repeaters or simply put they are ‘signal repeaters’.
- Voltage spikes can be induced on control cabling during fault conditions.
- MOFRs provide isolation of the timing signals between protection A/B systems and/or bays of equipment which are in different earth potential zones.
- Voltage spikes can be induced on control cabling during faults, MOFRs provide isolation to reduce the risk of time sync signal corruption due to the voltage spikes during fault conditions — precisely when accurate timing is vital.
- MOFRs provide isolation to reduce the safety risk and the risk of damage to equipment from voltage spikes through the time sync cabling.
- MOFRs simplify cabling installation by allowing a single time sync bus multi-dropping to a MOFR at the top of bays of IEDs in each earth potential zone.
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I am using AM IRIG-B but my relays are not syncing. Why?
- IEEE1344 extensions (providing year information to the IRIG-B code) may need to be turned on
- The AM IRIG-B output requires a termination resistor at the far end of the line. Without the termination resistor, the signal can be too high. Typically, a 120 ohm resistor is used
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How many IEDs can I drive per output?
It depends on the load of each IED but typically:
- TCG 01 — each TTL output can drive 10 - 20 IED's and AM IRIG-B output can drive 20 - 30 IED's
- TTM 01 — each TTL output can drive 10 - 20 IED's and AM IRIG-B output can drive 20 - 30 IED's
- MOFR 01 — each TTL output can drive 10 - 15 IED's and AM IRIG-B output can drive 20 - 30 IED's
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I am confused about the use of the term "RS232" to describe outputs that don't seem to be serial data. Please Explain?
- The RS232 standard was originally laid down to cover all of the aspects involved in implementing a serial
communications link. It included specification of the physical connector types, the pin-out of the connectors,
and the signaling function of each pin, the permissible range of signaling voltage levels, rise and fall times
of the signals, output current drive capacity and input impedance. It also described several forms of serial
data transmission that can be implemented in accordance with the standard.
So, describing a particular signal as "RS232" output does NOT automatically imply that it is a serial data
transmitter output - but merely that it has the particular electrical characteristics defined under the RS232
standard. Most true RS232 ports have a number of signal lines. In addition to the transmit and receive data
lines (TxD and RxD), they commonly have RTS, CTS, DSR, DTR and CD - none of which are serial transmission lines,
but rather are logical status signals.
For example, the "S" form of TTM01 has two output signals, both of which are implemented using RS232 level
signaling (+|-9V) and both of which use a common pin for the signal return. They are correctly described in
the datasheet as RS232 level outputs. One of these outputs is a true serial data transmitter, and carries serial
data strings (the same selection as is available for the serial output on TCG01). The other output can be
programmed for pulses, time codes etc and is identical in electrical form and signal output options to TCG01 P4,
pin 1 output.
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What are the voltage ranges for power supplies and are they each AC or DC?
- Low Voltage Range 12-36 DC/ 16-24 AC
- Medium Voltage Range 20-72 DC/ 24-48 AC
- High Voltage Range 90-360 DC/ 110-240 AC
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How many outputs does a TCG-01 GPS Clock have?
Standard TCG01 GPS Clock:
- 3 programmable
- 1 AM-IRIG std
- 1 status relay
TCG01 with GPS Clock Option N:
- 3 programmable
- 1 AM-IRIG std
- 1 status relay
- Network Time Server port (NTP)
TCG01 GPS Clock with Multi-port hub:
- 3 programmable
- 1 AM-IRIG std
- 1 status relay
- Multi-port hub provides 4 outputs each switchable between unmodulated and AM IRIG-B,
plus one additional programmable output.
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Can Tekron GPS Clocks be connected in series to provide additional outputs?
TCG-01: Yes
TTM-01: No
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What is the accuracy of Tekron GPS Clocks in holdover mode?
TCG01: 45 minutes with < 50 uS error
TTM01: 45 minutes with < 100 uS error
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