serial cables
- Thread starter llacy
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thibault
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- Oct 25, 2009
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lacy311,
Null Modem cables should not be used in a Skyview Net Device connection. These are the EFIS to EFIS and EFIS to ADAHRS, EMS, and/or ARINC boxes. Instead you need "straight through cables". In these, each pin has the same wire, in the same position, at both ends.
Null modem cables swap TX and RX wire positions from one end to the other. They are used in other (usually desktop PC) systems to connect two serial devices together. In this way when one device transmits on TX it is received by the other device on RX. This has no place in Skyview.
Take a careful look at the Installation Manual for more info.
Null Modem cables should not be used in a Skyview Net Device connection. These are the EFIS to EFIS and EFIS to ADAHRS, EMS, and/or ARINC boxes. Instead you need "straight through cables". In these, each pin has the same wire, in the same position, at both ends.
Null modem cables swap TX and RX wire positions from one end to the other. They are used in other (usually desktop PC) systems to connect two serial devices together. In this way when one device transmits on TX it is received by the other device on RX. This has no place in Skyview.
Take a careful look at the Installation Manual for more info.
- Joined
- Mar 23, 2005
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- 13,226
We understand the confusion - the DB9 connectors that SkyView uses as SkyView Network are much more commonly used on PCs as "RS-232 serial". However, on SkyView, the DB9 connectors on the SkyView displays, and most SkyView modules, are NOT "RS-232 serial". Thus any cable that is intended for "RS-232 serial" should probably not be used.
Some major differences between SkyView Network cables and "RS-232 serial" cables:
[list bull-blackball][*]"RS-232 serial" cables often don't include all wires / pins, often only Pins 2, 3, and 5.
[*]As Tom Thibault pointed out, "RS-232 serial" cables are often not wired pin-to-pin, as SkyView Network requires.
[*]SkyView Network carries power, and depending on the specific cable (location in the SkyView network), substantial enough power to cause an "RS-232 serial" cable to fail.
[*]Because of the high data rate, a SkyView Network cable has the two data pairs twisted together in a specific, repeated pattern (8-10 twists per foot), "RS-232 serial" cables do not have this twist.
[*]"RS-232 serial cables" are usually manufactured inexpensively; SkyView Network cables have all conductors specified as 22 AWG.
[*]SkyView Network cables, as manufactured by Dynon Avionics, are made of wires with Tefzel insulation and jacket; if they're exposed to fire, the resulting smoke is non-toxic.
[/list] Thus... don't use "RS-232 serial" cables in your SkyView system.
If you're lucky, your "RS-232 serial" Null Modem cable just swapped Pins 2 and 3, which are both ground in SkyView Network and there won't be any damage to the module. If you're unlucky, your particular "RS-232 serial" Null Modem cable may include pins in addition to 2, 3, and 5 and thus may have damaged the module that you connected using this cable. It depends on how that particular cable was wired. If so, the "RS-232 serial" cable connected power from the SkyView display to a pin on the module that was intended for data. If this happened, unfortunately it's not covered under warranty - contact Dynon Avionics Technical Support to arrange for a Return Material Authorization (RMA) - 425-402-0433 or support AT dynonavionics DOT com.
Dynon Avionics offers a 1.5 foot SkyView Network cable - SV-NET-1.5CC - contact Dynon Avionics Sales or any Dynon Avionics dealer to purchase.
Some major differences between SkyView Network cables and "RS-232 serial" cables:
[list bull-blackball][*]"RS-232 serial" cables often don't include all wires / pins, often only Pins 2, 3, and 5.
[*]As Tom Thibault pointed out, "RS-232 serial" cables are often not wired pin-to-pin, as SkyView Network requires.
[*]SkyView Network carries power, and depending on the specific cable (location in the SkyView network), substantial enough power to cause an "RS-232 serial" cable to fail.
[*]Because of the high data rate, a SkyView Network cable has the two data pairs twisted together in a specific, repeated pattern (8-10 twists per foot), "RS-232 serial" cables do not have this twist.
[*]"RS-232 serial cables" are usually manufactured inexpensively; SkyView Network cables have all conductors specified as 22 AWG.
[*]SkyView Network cables, as manufactured by Dynon Avionics, are made of wires with Tefzel insulation and jacket; if they're exposed to fire, the resulting smoke is non-toxic.
[/list] Thus... don't use "RS-232 serial" cables in your SkyView system.
If you're lucky, your "RS-232 serial" Null Modem cable just swapped Pins 2 and 3, which are both ground in SkyView Network and there won't be any damage to the module. If you're unlucky, your particular "RS-232 serial" Null Modem cable may include pins in addition to 2, 3, and 5 and thus may have damaged the module that you connected using this cable. It depends on how that particular cable was wired. If so, the "RS-232 serial" cable connected power from the SkyView display to a pin on the module that was intended for data. If this happened, unfortunately it's not covered under warranty - contact Dynon Avionics Technical Support to arrange for a Return Material Authorization (RMA) - 425-402-0433 or support AT dynonavionics DOT com.
Dynon Avionics offers a 1.5 foot SkyView Network cable - SV-NET-1.5CC - contact Dynon Avionics Sales or any Dynon Avionics dealer to purchase.
I wanted to shorten the serial cables from my Dynon EFIS screens reduce the bulk of the connections. I ordered a 1tf serial cable DB9 female to female and they don't work. What does null modem mean and does that change the pinout of the cables