Status in source: current.
Technical details
{
"smi_kind": "OBJECT-TYPE",
"definition": [
"zhoneVaIfEMCfgType",
"OBJECT-TYPE",
"SYNTAX",
"INTEGER",
"{",
"typeI",
"(",
"1",
")",
",",
"typeII",
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"2",
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",",
"typeIII",
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",",
"typeIV",
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"typeIIE",
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"typeIIM",
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"typeTO",
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"}",
"MAX-ACCESS",
"read-write",
"STATUS",
"current",
"DESCRIPTION",
"\"Specifies the E&M Lead Signaling type. LEGEND: V = -48V /\\/\\/ = detector/resister X = normally open relay contact + = normally closed relay contact G = ground SB = Signal Battery SG = Signal Ground typeI - Leads: E (output, relay to ground) M (input, referenced to ground) The tie line equipment (switch/router/etc) generates the E-signal to the PBX type grounding the E-lead. The tie line equipment detects the M-signal by detecting current flow to ground. A common ground must exist between the line equipment and the PBX. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | M: V----X-----|---/\\/\\/--G typeII - Leads: E (output, relay to SG) M (input, referenced to ground) SB (feed for M, connected to -48V) SG (return for E, galvanically isolated from ground) This interface requires no common ground between the equipment, thus avoiding ground loop noise problems. E-signal is generated toward the PBX by connecting it to SG. M-signal is indicated by the PBX connecting it to SB. While this interface does NOT require a common ground, it does have the tendency to inject noise into the audio paths since it is asymmetrical with respect to current flow between devices. PBX | TIE LINE | E: V--/\\/\\/---|-----X---- | | SG: G----------|---------- | M: ----X-----|---/\\/\\/--G | | SB: ----------|----------V typeIII - Leads: E (output, relay to ground) M (input, referenced to ground) SB (connected to -48V) SG (connected to ground) This interface operates similar to type I with respect to the E-signal. The M-signal, however, is indicated by the PBX connecting it to SB on assertion, and alternately connecting it to SG during inactivity. Unfortunately, a common ground must be shared between the equipment. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | SG: ----------|----------G + | M: ----------|---/\\/\\/--G X | SB: ----------|----------V typeIV - Leads: E (output, relay to SG) M (input, referenced to -48V) SB (feed for M, connected to ground) SG (return for E, galvanically isolated from ground) This interface is fully symmetrical; it does not require a common ground, does not inject noise into audio paths, and can be connected back to back by swapping E/SG for M/SB. E-signal is indicated to the PBX by connecting it to SG. M-signal is provided by the PBX connecting it to SB. PBX | TIE LINE | E: V--/\\/\\/---|-----X---- | | SG: G----------|---------- | M: ----------|---/\\/\\/--V X | SB: ----------|----------G typeV - Leads: E (output, relay to ground) M (input, referenced to -48V) Type V line equipment indicates E-signal to the PBX by grounding the E-lead. The PBX indicates M-signal by grounding the M-lead. This interface does require a common ground, but does allow back to back connections by swapping E for M. This interface is quasi-symmetric in that while the line is up, current flow is more or less equal between the PBX and line equipment. But noise injection is still a problem. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | M: G-----X----|---/\\/\\/--V | The default value of this object is typeI(1). \"",
"REFERENCE",
"\"EIA/TIA-464B: Sections 4.2.3 E&M Lead Signaling. \"",
"::=",
"{",
"zhoneVaIfEMCfgEntry",
"3",
"}"
],
"syntax_tree": [
[
"SimpleSyntax",
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[
"enumSpec",
[
[
"typeI",
1
],
[
"typeII",
2
],
[
"typeIII",
3
],
[
"typeIV",
4
],
[
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],
[
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],
[
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],
[
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]
]
]
],
null,
[
"MaxAccessPart",
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],
[
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],
[
"DESCRIPTION",
"Specifies the E&M Lead Signaling type. LEGEND: V = -48V /\\/\\/ = detector/resister X = normally open relay contact + = normally closed relay contact G = ground SB = Signal Battery SG = Signal Ground typeI - Leads: E (output, relay to ground) M (input, referenced to ground) The tie line equipment (switch/router/etc) generates the E-signal to the PBX type grounding the E-lead. The tie line equipment detects the M-signal by detecting current flow to ground. A common ground must exist between the line equipment and the PBX. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | M: V----X-----|---/\\/\\/--G typeII - Leads: E (output, relay to SG) M (input, referenced to ground) SB (feed for M, connected to -48V) SG (return for E, galvanically isolated from ground) This interface requires no common ground between the equipment, thus avoiding ground loop noise problems. E-signal is generated toward the PBX by connecting it to SG. M-signal is indicated by the PBX connecting it to SB. While this interface does NOT require a common ground, it does have the tendency to inject noise into the audio paths since it is asymmetrical with respect to current flow between devices. PBX | TIE LINE | E: V--/\\/\\/---|-----X---- | | SG: G----------|---------- | M: ----X-----|---/\\/\\/--G | | SB: ----------|----------V typeIII - Leads: E (output, relay to ground) M (input, referenced to ground) SB (connected to -48V) SG (connected to ground) This interface operates similar to type I with respect to the E-signal. The M-signal, however, is indicated by the PBX connecting it to SB on assertion, and alternately connecting it to SG during inactivity. Unfortunately, a common ground must be shared between the equipment. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | SG: ----------|----------G + | M: ----------|---/\\/\\/--G X | SB: ----------|----------V typeIV - Leads: E (output, relay to SG) M (input, referenced to -48V) SB (feed for M, connected to ground) SG (return for E, galvanically isolated from ground) This interface is fully symmetrical; it does not require a common ground, does not inject noise into audio paths, and can be connected back to back by swapping E/SG for M/SB. E-signal is indicated to the PBX by connecting it to SG. M-signal is provided by the PBX connecting it to SB. PBX | TIE LINE | E: V--/\\/\\/---|-----X---- | | SG: G----------|---------- | M: ----------|---/\\/\\/--V X | SB: ----------|----------G typeV - Leads: E (output, relay to ground) M (input, referenced to -48V) Type V line equipment indicates E-signal to the PBX by grounding the E-lead. The PBX indicates M-signal by grounding the M-lead. This interface does require a common ground, but does allow back to back connections by swapping E for M. This interface is quasi-symmetric in that while the line is up, current flow is more or less equal between the PBX and line equipment. But noise injection is still a problem. PBX | TIE LINE | E: V--/\\/\\/---|-----X----G | M: G-----X----|---/\\/\\/--V | The default value of this object is typeI(1)."
],
[
"REFERENCE",
"EIA/TIA-464B: Sections 4.2.3 E&M Lead Signaling."
],
null,
null,
null
]
}