DM3 Configuration File Reference: 1.3.8. [CAS] Section

1.3.8. [CAS] Section

The Channel Associated Signaling (CAS) component resides on the signal processor. It is responsible for managing the generation and detection of digital line signaling functions required to manage voice channels. Each CAS instance corresponds to the CHP instance of the same voice channel.

The [CAS] section of the CONFIG file is a subcomponent of the [TSC] section. Commands in the [CAS] section define the signaling types used by a CAS protocol and the [TSC] section assigns these signaling type to voice channels. For example, many CAS protocols use off-hook and wink signals, which can be defined in this section. For an explanation of the [TSC] section of the CONFIG file, see Section 1.3.11, [TSC] Section.

Note: The CAS signaling parameters should only be modified by experienced users if the default settings do not match what the line carrier or PBX is sending or expecting for the line protocol configuration running on the card.

For information about specific CAS parameter, see the following sections:

Section 4.9, [CAS] Parameters for T-1 E&M Signals.
Section 4.10, [CAS] Parameters for T-1 Loop Start Signals.
Section 4.11, [CAS] Parameters for T-1 Ground Start Signals.

CAS parameters are defined using the following signal definition types:

Transition Signal - the current signaling state changes to a new signaling state.
Pulse Signal - the current signaling state changes to a new signaling state, and then reverts to the original signaling state.
Train Signal - the signaling state alternates between two predefined signaling states in a regular defined pattern (series of pulses).
Sequence Signal - the signaling state is defined by a set of train signals.

Transition Signal

The transition command defines an ABCD-bit transition from one state to another. It is used to define the CAS transition signals required by a protocol. The transition command uses the following syntax:
transition = SigId, Preval, PostVal, PreTM, PostTM 
where,

SigId is a unique identifier (parameter number) of the transition signal. The Channel Protocol (CHP) uses the SigId to recognize the transition when it is received, and also to generate the transition when needed.

Note: SigId should not be modified by the user.

PreVal defines the ABCD bit states on the line before the transition occurs. The four least significant bits represent the ABCD signaling bits (0 or 1). The four most significant bits represent a mask (A'B'C'D') that specifies if each corresponding signaling bit value counts. If a mask bit is set to 1, the corresponding signaling bit is counted. If a mask bit is set to 0, the corresponding signaling bit is ignored.

PostVal defines the ABCD bit states on the line after the transition occurs. The format of this field is the same as the PreVal field.
PreTm defines the minimum amount of time, in milliseconds, for the duration of the pre-transition interval.
PostTm defines the minimum amount of time, in milliseconds, for the duration of the post-transition interval.

Transition Example

The following is an example of a transition command that defines a transition signal:
transition = 0xC15CA001, 0xF0,0xFF, 100, 300 
In the example shown, the transition signal is defined as having the following values:

SigId = 0xC15CA001 - Defines the CAS T-1 E&M transition signal off-hook.
PreVal = 0xF0 (11110000) - Defines the mask as having a hexadecimal value of F (1111) and the signaling bits as having a hexadecimal value of 0 (0000). Since all of the mask bits are 1, all of the signaling bits are significant. Thus, the A, B, C, and D bits all have a value of 0 before the transition.
PostVal = 0xFF (11111111) - Defines both the mask and the signaling bits as having a hexadecimal value of F (1111). Since all of the mask bits are 1, all of the signaling bits are significant. Thus, the A, B, C, and D bits all have a value of 1 after the transition.
PreTm = 100 ms - Specifies that the PreVal signaling bits must be present for at least 100 milliseconds before they transition to the OnVal signaling values.
PostTm = 300 ms - Specifies that the PostVal signaling bits must be present for at least 300 milliseconds before the signal is reported to the protocol (or if the signal is being sent, then the CAS subcomponent ensures that the OffVal signaling value is generated for at least 300 milliseconds).

Figure 2 is a graphical representation of this signal definition.

Figure 2. Example of Off-hook Transition Signal (0xC15CA001)

Pulse Signal

The pulse command defines an ABCD-bit transition from one state to another, and then back to the original state. It is used to define the CAS pulse signals required by a protocol. The pulse command uses the following syntax:
pulse = SigId, OffVal, OnVal, PreTm, MinTm, NomTm, MaxTm, PostTm 
where,

SigId is a unique identifier (parameter number) of the pulse signal. The Channel Protocol (CHP) uses the SigId to recognize the pulse when it is received, and also to generate the pulse when needed.

Note: SigId should not be modified by the user.

OffVal defines the ABCD bit states on the line before the transition occurs. The four least significant bits represent the ABCD signaling bits (0 or 1). The four most significant bits represent a mask (A'B'C'D') that specifies if each corresponding signaling bit value counts. If a mask bit is set to 1, the corresponding signaling bit is counted. If a mask bit is set to 0, the corresponding signaling bit is ignored.

OnVal defines the ABCD bit states on the line during the pulse. The format of this field is the same as the OffVal field.
PreTm defines the minimum time, in milliseconds, for the duration of the pre-pulse interval.
MinTm defines the minimum time, in milliseconds, for the duration of the pulse interval.
NomTm defines the nominal time, in milliseconds, for the duration of the pulse interval.
MaxTm defines the maximum time, in milliseconds, for the duration of the pulse interval.
PostTm defines the minimum time, in milliseconds, for the duration of the end-of-pulse interval.

Pulse Example

The following is an example of a pulse command that defines a pulse signal:
pulse = 0xC15CA011, 0xF0, 0xFF, 100, 220, 250, 280, 100 
In the example shown, the pulse signal is defined as having the following values:

SigId = 0xC15CA011 - Defines the CAS T-1 E&M pulse signal Wink.
OffVal = 0xF0 - Defines the mask as having a hexadecimal value of F (1111) and the signaling bits as having a hexadecimal value of 0 (0000). Since all of the mask bits are 1, all of the signaling bits are significant. Thus, the A, B, C, and D bits all have a value of 0 before the transition from the OffVal to the OnVal, and after the transition from the OnVal to the OffVal.
OnVal = 0xFF - Defines both the mask and the signaling bits as having a hexadecimal value of F (1111). Since all of the mask bits are 1, all of the signaling bits are significant. Thus, the A, B, C, and D bits all have a value of 1 after the transition to the OnVal.
PreTm = 100 ms - Specifies that the OffVal signaling bits must be present for at least 100 milliseconds before they transition to the OnVal signaling values.
MinTm = 220 ms - Specifies that the OnVal signaling bits must be present for at least 220 milliseconds before they transition to the OffVal signaling values.
NomTm = 250 ms - Specifies that the OnVal signaling bits are generated for 250 milliseconds before transitioning to the OffVal signaling values.
MaxTm = 280 ms - Specifies that the OnVal signaling bits must be present for no longer than 280 milliseconds before they transition to the OffVal signaling values.
PostTm = 100 ms - Specifies that the OffVal signaling bits must be present for at least 100 milliseconds before the signal is reported to the protocol (or if the signal is being sent, then the CAS component ensures that the OffVal signaling value is generated for at least 100 milliseconds).

Figure 3 is a graphical representation of this signal definition.

Figure 3. Example of Wink Pulse Signal (0xC15CA011)

Train Signal

The train command defines a set of transitions from one signaling state to another in a predefined pattern (set of pulses). It is used to define CAS signals required by a protocol. The train command uses the following syntax:
train = SigId, OffVal, OnVal, PulseTmlMin, PulseTmMax, PulseTmNom, preTm, interTmMin, interTmMax, interTmNom, postTm, digitCount, pulseCount, label, pulseCount, label, ... 
where,

SigId is a unique identifier (parameter number) of the train signal. The Channel Protocol (CHP) uses the SigId to recognize the train when it is received, and also to generate the train when needed.

Note: SigId should not be modified by the user.

OffVal defines the ABCD bit states on the line before the transition occurs. The four least significant bits represent the ABCD signaling bits (0 or 1). The four most significant bits represent a mask (A'B'C'D') that specifies if each corresponding bit value count. If a mask bit is set to 1, the corresponding signaling bit is counted. If a mask bit is set to 0, the corresponding signaling bit is ignored.

OnVal defines the ABCD bit states on the line during one pulse of the train. The format of this field is the same as the OffVal field.
pulseTmMin defines the minimum time, in milliseconds, for the duration of the pulse interval.
pulseTmMax defines the maximum time, in milliseconds, for the duration of the pulse interval.
pulseTmNom defines the nominal time, in milliseconds, for the duration of the pulse interval.
preTm defines the minimum time, in milliseconds, for the duration of the pre-train interval.
interTmMin defines the minimum time, in milliseconds, for the duration of the inter-pulse interval.
interTmMax defines the maximum time, in milliseconds, for the duration of the inter-pulse interval.
interTmNom defines the nominal time, in milliseconds, for the duration of the inter-pulse interval.
postTm defines the maximum time, in milliseconds, for the duration of the post-train interval.
digitCount defines the number of digit definitions in the train. The pulse count for each digit (ASCII character) is defined by the label pairs following digitCount.
pulseCount defines the number of train pulses that define the digit (ASCII character) identified by the label parameter.
label defines the digit (ASCII character) associated with the corresponding pulseCount value.

Train Example

The following is an example of a train command that defines a train signal:
train = 0xC15CA032, 0xCC, 0xC4, 31, 33, 32, 600, 62, 66, 64, 20, 12, 10, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 11, #, 12, * 
where,

SigId = 0xC15CA032 - Defines the CAS T-1 loop start train signal parameter.
OffVal = 0xCC - Defines both the mask and the signaling bits as having a hexadecimal value of C (1100). Since only mask bits A and B have a value of 1, only signaling bits A and B are significant. Thus, the A and B bits both have a value of 1 before the transition from the OffVal to the OnVal.
OnVal = 0xC4 - Defines the mask as having a hexadecimal value of C (1100) and the signaling bits as having a hexadecimal value of 4 (0100). Since mask bits A and B have a value of 1, signaling bits A and B are significant. Thus, the A bit has a value of 0 and the B bit has a value of 1 after the transition to the OnVal.
pulseTmMin = 31 - Specifies that the OnVal signaling bits must be present for at least 31 milliseconds before they transition to the OffVal signaling values.
pulseTmMax = 33 - Specifies that the OnVal signaling bits must be present for no longer than 33 milliseconds before they transition to the OffVal signaling values.
pulseTmNom = 32 - Specifies that the OnVal signaling bits must be present for 32 milliseconds before they transition to the OffVal signaling values.
preTm = 600 - Specifies that the OffVal signaling bits must be present for 600 milliseconds before the train signal begins.
interTmMin = 62 - Specifies that the OffVal signaling bits must be present for at least 62 milliseconds before they transition to the OnVal signaling values.
interTmMax = 66 - Specifies that the OffVal signaling bits must be present for no longer than 66 milliseconds before they transition to the OnVal signaling values.
interTmNom = 64 - Specifies that the OffVal signaling bits must be present for 64 milliseconds before they transition to the OnVal signaling values.
postTm = 20 - Specifies that the OffVal signaling bits must be present for 20 milliseconds before the signal is reported to the protocol (or if the signal is being sent, then the CAS component ensures that the OffVal value is generated for at least 20 milliseconds).
digitCount = 12 - Specifies that 12 digits/characters are defined by this train signal.
pulseCount, label pairs = 10,0 1,1 2,2 3,3 4,4 5,5 6,6 7,7 8,8 9,9 11,# 12,* - The first pair indicates that 10 pulses correspond to the digit "0", the next pair indicates that 1 pulse corresponds to the digit "1', and the last pair indicates that 12 pulses correspond to the ASCII character "*".

Figure 4 is a graphical representation of this signal definition.

Figure 4. Example of T-1 Loop Start Train Signal (0xC15CA032)

Sequence Signal

The sequence command defines a set of train signals. It is used to define CAS signals required by a protocol. The sequence command uses the following syntax:
sequence = SigId, TrainSigId, preTm, interTmMin, interTmMax, interTmNom, postTm 
where,

SigId is a unique identifier (parameter number) of the sequence signal. The Channel Protocol (CHP) uses the SigId to recognize the sequence when it is received, and also to generate the sequence when needed.

Note: SigId should not be modified by the user.

TrainSigId defines the train signal that the sequence signal uses.
preTm defines the minimum time, in milliseconds, for the duration of the pre-sequence interval.
interTmMin defines the minimum time, in milliseconds, for the duration of the inter-train interval.
interTmMax defines the maximum time, in milliseconds, for the duration of the inter-train interval.
interTmNom defines the nominal time, in milliseconds, for the duration of the inter-train interval.
postTm defines the minimal time, in milliseconds, for the duration of the post-sequence interval.

Sequence Example

The following is an example of a sequence command that defines a sequence signal:
sequence = 0xC15CA033, 0xC15CA032, 720, 640, 680, 660, 1600 
where,

SigId = 0xC15CA033 - Specifies the CAS T-1 loop start sequence signal parameter.
TrainSigId = 0xC15CA032 - Specifies the train signal definition that the sequence signal uses.
preTm = 720 - Specifies that the OffVal signaling bits (as defined in the train definition) must be present for 720 milliseconds before the sequence signal begins (that is, before the first train signal begins).
interTmMin = 640 - Specifies that the OffVal signaling bits (as defined in the train definition) must be present for at least 640 milliseconds between train signals.
interTmMax = 680 - Specifies that the OffVal signaling bits (as defined in the train definition) must be present for no longer than 680 milliseconds between train signals.
interTmNom = 660 - Specifies that the OffVal signaling bits (as defined in the train definition) must be present for 660 milliseconds between train signals.
postTm = 1600 - Specifies that the OffVal signaling bits (as defined in the train definition) must be present for 1600 milliseconds before the signal is reported to the protocol (or if the signal is being sent, then the CAS component ensures that the OffVal value is generated for at least 1600 milliseconds).

Figure 5 is a graphical representation of this signal definition.

Figure 5. Example of T-1 Loop Start Sequence Signal (0xC15CA033)

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