DECnet-Plus
Network Control Language Reference

The default value depends on the value of the characteristic communications mode. If communications mode is asynchronous, the default value of this characteristic is also asynchronous. If the value of communications mode is synchronous, the default value of this characteristic is hdlc.

modem protocol type (Digital UNIX)

profile

rate select

This characteristic is supported only if the characteristic modem control is full, and if the characteristic modem options includes rateselect.

speed

• When the value of the clock characteristic is internal.
• When a null modem cable is detected.
• When using a loopback mode that uses internal clocking.

successful call indication timer

suppress test indicator

You should set this characteristic to true in cases where the transitions of this signal are not produced by entering the test mode, so that this signal should be ignored.

transmit holdoff timer

cable faults

Total number of times the communications cable was detected as missing or invalid.

creation time

Time at which this entity was created.

device errors

Total number of times a potential device error has been reported.

framing errors

Total number of framing errors detected on the line. This counter is not supported if the characteristic communications mode is synchronous.

losses of carrier

Total number of times the carrier on the line was lost. This attribute is not supported if the characteristic modem control is set to none.

losses of clock

Total number of times the transmit or receive clock was lost.

outgoing call failures (Digital UNIX)

Total number of times an outgoing call failed to connect.

rate fallbacks

Number of times the DTE changed from the high data rate to the low (alternate) rate. This counter is supported only if the characteristic modem options includes rate select, and if the characteristic modem control is full.

test indications

Number of times the DCE was put into test mode by the remote system. This attribute is not supported if the characteristic modem control is set to none.

times cable detected

Total number of times a valid communications cable was detected following a an error counted by the counter cable faults.

times dce not ready

Total number of times a dce not ready event occurred. This attribute is not supported if the characteristic modem control is set to none.

times reset (OpenVMS)

Number of times the data link client has performed a line reset.

transmit enable timeouts

Number of times the DCE failed to assert clear to send in response to request to send. This attribute is not supported if the characteristic modem control is set to none.

16.3.5 Identifier Attributes

name

Simple name assigned to the line when it is created.

actual speed

Actual speed of the line, in bits per second. For internal clocking on some microcoded devices, a value of 0 indicates that the device has selected a speed appropriate for the connected interface. For external clocking, a value of 0 indicates that the speed is unknown.

device availability (OpenVMS)

Indicates whether the hardware device associated with the named communications port is installed. Support is mandatory on systems that support line card hot swap. When device availability has the value no device, the interface state takes the value pending DTE Ready and the interface type attribute takes the value unknown.

interface state

State of the physical interface on the line.

connected	A switched line is connected but not ready to transmit or receive data.
connecting	Call setup on a switched line is in progress.
disconnecting	Call clear on a switched line is in progress.
dte not ready	The entity is disabled.
dte ready	The DTE is ready, but the DCE is not ready.
full enabled	The line is enabled for data transmission and reception.
pending dte ready	The entity is enabled but the ready state cannot be entered. For example, the communications cable is not connected.
ready	Both DTE and DCE are ready.
receive enabled	The line is ready to receive data.
transmit enabled	The line is ready for data transmission.

interface type

Type of the physical interface connection.

loopback	A loopback connector has been detected on the interface.
no cable	No cable is connected to the interface.
null modem	A null modem cable is connected to the interface.
rs232c	A cable conforming to the RS-232-C standard is attached.
rs422	A cable conforming to the RS-422 standard is attached.
rs423-v24	This value appears where a cable is attached but the connector cannot distinguish between the RS-423 and V.24 standards.
rs449	A cable conforming to the RS-449 standard is attached.
unknown	A cable is attached but its type is not known
v28	A cable conforming to any of the CCITT V.24, V.28 standards, the IS 2110 standard, or the EIA-232-D standard.
v35	A cable conforming to the V.35 standard is attached.
x21	A cable conforming to the X.21 standard is attached.

loopback mode

Type of loopback in use on the line. The value of this status attribute is determined by the startloop and stoploop commands.

connector	Data is looped through a loopback connector attached to the communications device.
device	Data is looped in the communications device.
driver	Data is looped in the driver of the communications device.
external	Data is looped through a null modem or a modem in loopback mode.
local	The communications device has switched its local modem into loopback mode.
null	The line is not in loopback mode.
remote	The communications device has switched the remote modem into loopback mode.

modem type

String identifying the local modem. If this status attribute has no value, the type could not be determined.

state

Specifies the status of the modem connect line entity.

off	The line has been disabled.
on	The line has been enabled.

uid

Entity's unique identifier, which is generated when the entity is created.

The modem connect line entity in the Modem Connect module has an extra set of status attributes that let you examine the instantaneous status of the interchange circuits on the line.

These circuit attributes are known by different names in the various interface standards. Table 16-1 shows how the attribute names used in NCL correspond to those used in the interface standards. For instance, the data terminal ready attribute is the name used for the CCITT V.24 circuit 108/2, the EIA-232-D CD circuit, the RS-499 TR circuit, and so on.

When entering commands, always use the NCL attribute name. When displayed, each attribute has one of the following values:

asserted	The circuit is asserted.
not applicable	The circuit does not exist on the interface.
not asserted	The circuit is not asserted.
unknown	The modem cable is not connected or is invalid.

<online chunk>

Table 16-1 Modem Connect Line Interchange Circuits

NCL Attribute Name	Circuit	Description
CCITT V.24
carrier detect	109	Data channel received line signal detector
clear to send	106	Ready for sending
data set ready	107	Data set ready
data terminal ready	108/2	Data terminal ready
local loopback	141	Local loopback
remote loopback	140	Loopback/maintenance test
request to send	105	Request to send
ring indicator	125	Calling indicator
signaling rate indicator	112	Data signal rate selector (DCE)
signaling rate selector	111	Data signal rate selector (DTE)
test mode	142	Test indicator
DIN 66020 Blatt 1
carrier detect	M5	---
clear to send	M2	---
data set ready	M1	---
data terminal ready	S1.2	---
local loopback	PS3	---
remote loopback	PS2	---
request to send	S2	---
ring indicator	M3	---
signaling rate indicator	Not supported	---
signaling rate selector	S4	---
test mode	PM1	---
EIA-232-D
carrier detect	CF	Received line signal detector
clear to send	CB	Clear to send
data set ready	CC	DCE ready
data terminal ready	CD	DTE ready
local loopback	LL	Local loopback
remote loopback	RL	Remote loopback
request to send	CA	Request to send
ring indicator	CE	Ring indicator
signaling rate indicator	CI	Data signal rate selector (DCE)
signaling rate selector	CH	Data signal rate selector (DTE)
test mode	TM	Test mode
RS-232-C
carrier detect	---	Received line signal detector
clear to send	---	Clear to send
data set ready	---	Data set ready
data terminal ready	---	Data terminal ready
local loopback	---	Not supported
remote loopback	---	Not supported
request to send	---	Request to send
ring indicator	---	Ring indicator
signaling rate indicator	---	Data signal rate selector (DCE)
signaling rate selector	---	Data signal rate selector (DTE)
test mode	---	not supported
RS-449
carrier detect	RR	Receiver ready
clear to send	CS	Clear to send
data set ready	DM	Data mode
data terminal ready	TR	Terminal ready
local loopback	LL	Local loopback
remote loopback	RL	Remote loopback
request to send	RS	Request to send
ring indicator	IC	Incoming call
signaling rate indicator	SI	Signaling rate indicator
signaling rate selector	SR	Signaling rate selector
test mode	TM	Test mode

16.3.8 Event Messages

cable detected

Generated when a valid communication cable is detected following a cable fault event.

Arguments:

current interface type	Type of cable detected.
	loopback	A loopback connector has been detected.
	null modem	A null modem has been detected.
	rs232c	A cable conforming to the RS-232-C standard has been detected.
	rs449	A cable conforming to the RS-449 standard has been detected.
	rs422	A cable conforming to the RS-422 standard has been detected.
	rs423-v24	A cable is attached, but the connector cannot distinguish whether it conforms to RS-423 or V.24 standards.
	v.28	A cable conforming to any of the CCITT V.24, CCITT V.28, IS2110, or EIA-232-D standards has been detected.
	v.35	A cable conforming to the V.35 standard has been detected.
	x.21	A cable conforming to the X.21 standard has been detected.
previous interface type	Previous type of cable detected.
	no cable	No cable was attached to the interface.
	unknown	A cable was attached, but its type was unknown.

cable fault

Generated each time the communications cable is detected as missing or invalid.

Arguments: The call reference argument is present only if the characteristic connection type is switched.

call reference	The call reference number of the call that was disconnected because of the fault.
previous interface type	Type of cable that was connected before the error was detected.
	loopback	A loopback connector.
	null modem	A null modem cable.
	rs232c	A cable conforming to the RS-232-C standard.
	rs422	A cable conforming to the RS-422 standard.
	rs423-v24	A cable is attached, but the connector cannot distinguish whether it conforms to RS-423 or V.24 standards.
	rs449	A cable conforming to the RS-449 standard.
	unknown	A cable was connected but its type was unknown.
	v.28	A cable conforming to any of the CCITT V.24, CCITT V.28, IS2110, or EIA-232-D standards.
	v.35	A cable conforming to the V.35 standard.
	x.21	A cable conforming to the X.21 standard.
reason	Reason that caused the event to occur.
	invalid cable	A cable is attached but it is not one of those recognized.
	no cable	No cable can be detected.

clock loss

Generated each time a loss of the transmit or receive clock is detected. Once this event occurs, the value of the interface state attribute changes to pending dte ready.

dce not ready

Generated each time a dce not ready condition is detected. Once this event occurs, the value of the interface state attribute changes to dte ready. This event does not occur if the characteristic modem control is set to none.

device error

A potential device error has been detected. This may be a temporary condition that means the device can continue to be used.

Argument:

reason

Reason for the failure. This is device specific.

framing error

Generated each time an asynchronous framing error occurs.

loss of carrier

Generated each time the carrier frequency is lost while receiving data. This event is not supported if the characteristic modem control is none.

rate fallback

Generated each time the DCE indicates that it is changing from the high data rate (as indicated by the speed characteristic) to the low data rate (as indicated by the alternate speed characteristic. This can occur if there is excessive noise when operating at the high data rate. This event is supported only when the modem has a rate selection capability.

reset (OpenVMS)

Generated each time the Data Link client represents a line reset by means of the service interface.

test indication

Generated each time the remote system tests the DCE. When this event occurs, the value of the interface state attribute changes to dte ready. This event is not supported if the characteristic modem control is none.

transmit enable timeout

Generated whenever the time to assert the clear to send signal (after receiving the request to send signal) is greater that that specified in the maximum enable transmit timer characteristic. This event is not supported if the characteristic modem control is none.

For startloop:

already in loopback

The modem connect line entity specified in the command is already in loopback mode. Check that you specified the correct entity. Reissue the command with the correct name.

constraint violation

One of the following constraints has been violated:

• The implementation does not support the requested loopback mode.
• The requested loopback mode is incompatible with the communications interface type.
• The line is half-duplex.

line disabled

This modem connect line entity is disabled.

For create:

communications port in use

Another entity has reserved the communications port specified in the command. Check that you specified the correct port. Reissue the command specifying another port or modify the other entity to use a different port.

For enable:

high speed mode selected

The line cannot be used while high-speed mode is selected.

This chapter describes all the commands you can use to manage the entities that constitute the Maintenance Operations Protocol (MOP) module. The MOP module is located in the Application layer described by the Digital Network Architecture (DNA). MOP has a direct connection with the Data Link layer; thus, for certain functions, MOP can bypass the higher layers in the DNA protocol tower. This is useful for nodes that do not (yet) have all the higher layers of DNA protocol towers installed. Functions provided by the MOP module include downline loading, upline dumping, and communications testing.

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   2-DEC-1996 12:48:08.06

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