Expansion Modules

Installing an expansion module in the FastPAD is described at the end of this chapter. The preceding sections describe installation considerations such as switch settings for each module.


Model No.	Description
VFC-01	8-16 kbps In-Line Voice/Fax Card
VFC-03	4.8-16 kbps Voice/Fax Card
FRAM-01	Frame Relay Access Module

The Voice/Fax expansion modules support a single Voice/Fax path between the FastPAD and an attached device.

Each FRAM-01 module provides three high-speed (up to 512 kbps) data channels. The following paragraphs describes each of the expansion modules that can be installed in a FastPAD.

Note

VFC-01 and VFC-03 expansion modules can be installed in the same FastPAD. However, the VFC-01 and VFC-03 can communicate only with the 16K ATC voice algorithm

In Line Voice Fax Card (VFC-01)

The VFC-01 Voice Fax Card plugs into any expansion card slot in a FastPAD and allows transmission of either voice or Group III fax over the private network. Each VFC-01 occupies one card slot; the FastPAD can support up to eight VFC-01 cards.

The VFC-01 connects with a single voice or fax source, via the RJ11 connector (FXS or FXO), or the RJ45 connector (E&M). When the local VFC-01 detects an off hook condition, a call is initiated. Once connected, the call is in voice mode.

The VFC-01 listens for fax tones from the answering fax machine. The answering fax machine provides a 2100 Hz tone which provides Called Station Identification. Alternately, the answering fax machine may send a 300 bps modem signal for Digital Signal Identification. Both signals originate at the called fax and describe the fax machine's capabilities to the calling fax machine. When either signal is received by the VFC-01, it will switch from voice to fax operation and continue with the fax protocol connection sequence.

If no fax tones are detected, the call remains in voice mode. When an on-hook condition is detected, the call is terminated and the VFC-01 returns to idle mode.

VFC-01 Hardware

The VFC-01 may be installed in any of the eight FastPAD expansion slots. The VFC-01 has both an RJ45 connector for interfacing with E&M (PBX multi-wire) circuits and an RJ11 connector for interfacing with FXS or FXO (two-wire) circuits.

Switch Settings

Note

Switch 1 is only read after a power up or after a system reset. After changing the S1 switch setting, a system reset is required in order for the new selection to become effective.

Usually, either position will provide acceptable performance. However, if excessive echoing is experienced, moving the jumper should help to alleviate the problem. No other jumpers are user configurable.

In Line Voice Fax Card (VFC-03)

The VFC-03 operates identically to the VFC-01 described above. The difference between the VFC-01 and VFC-03 are:


E&M Type	SW1	SW2	SW3	SW4
I	RIGHT	RIGHT	LEFT	LEFT
II	LEFT	RIGHT	RIGHT	LEFT
III	RIGHT	RIGHT	RIGHT	LEFT
IV	LEFT	RIGHT	RIGHT	LEFT
V	RIGHT	LEFT	RIGHT	RIGHT

LEFT/RIGHT positions are left or right facing the back of the unit where the switch is visible through the connector edge of the card.

VFC-03 Hardware

The VFC-03 may be installed in any of the eight FastPAD expansion slots. The VFC-03 has both an RJ45 connector for interfacing with E&M (PBX multi-wire) circuits and an RJ11 connector for interfacing with FXS or FXO (two-wire) circuits.

Jumper Settings

600 ohm impedance is normally used for FXS and E&M applications. Complex line impedance is normally used for FXO applications that connect to a PSTN. Usually, either position will provide acceptable performance. However, if excessive echoing is experienced, moving the jumper should help to alleviate the problem.

Two LEDs are located on the upper edge of the board. These LEDs have different meanings depending on the telephony interface configured under software control. When the card is configured for E&M operation, the red LED indicates the presence of the "M" lead when it is ON. The green LED indicates the presence of the "E" lead when it is ON. If the card is configured for FXS or FXO operating mode, the red LED (ON) indicates an off-hook condition at the local FastPAD. When the green LED is ON, it indicates a connection is established.

The rear of the VFC-03 includes an RJ45 connector for interfacing with E&M (multi-wire) circuits and an RJ11 connector for interfacing with two-wire circuits.

Frame Relay Access Module (FRAM-01)

The FRAM-01 Frame Relay Access Module can be installed in any available FastPAD expansion slot.

Each FRAM-01 supports three high-speed (up to 512 kbps) synchronous data channels that operate in H/SDLC or Frame Relay modes. (Changing a data channel from H/SDLC to Frame Relay requires a reset.) Devices are attached to the FRAM-01 with a special 68-pin triplex cable that ends in three DB-25 male connectors. Each channel can be configured as:

•

A normal synchronous mode (H/SDLC) data channel that connects DTE or DCE devices to the FastPAD or FastPAD Micro.

Only one channel can be configured as a high-speed composite link. (StrataCom recommends channel 2). When configured as a data channel, a channel can have the same functionality as the base unit data channels except it can be configured for much higher data rates, or it can be configured for Frame Relay. Selecting a FRAM-01 channel as a high-speed composite link disables the standard base card composite link.

When a FRAM-01 data channel is configured as a Frame Relay Port with multiple PVCs, the channel functions as an integrated Frame Relay Switch that includes the following features:

•

Provides different classes of frame relay services. Pure frame relay switch is extended with priorities, fragmentation, compression and encapsulation.

•

LMI supports link verification procedures (keep alive) and full status messages.

•

Congestion parameters ensure fair distribution of resources and enforcement of the Committed Information Rate (CIR).

When a frame relay switch port is configured active, it is assumed the composite link is connected to the integrated switch (i.e., no other base card or data card composite link can be configured).

Note

When the mode of a data channel is changed from H/SDLC mode (the default) to Frame Relay mode or vice versa, a system reset is required.

When a FRAM-01 data channel is configured as a frame relay switch port, data rates in the range 1.2K to 512 kbps can be selected.

FRAM-01 Hardware

A red LED is located just below the jumper labeled J2 on the upper edge of the FRAM-01. This is a hardware diagnostics LED that will flash momentarily at power on. During normal operations, this LED should be on solid. If this LED flashes continuously at any time after the power-up sequence, it indicates a hardware failure. If this is the case, call StrataCom Customer Support for assistance.

A 68-pin connector is located on the rear of the FRAM-01. This connector and the triplex cable (Part # 5050250-012) included with the card are used to attach either DTE or DCE devices to the FastPAD.

There are three connectors on the card that can be used to attach electrical interface adapters for each of the three data channels. The FRAM-01 interface adapter card converts the standard RS-232 interface for a selected data channel to V.35, V.11/X.21 or RS-449/422. The triplex cable provided with the card supports all three interfaces. There are three connectors on the interface adapter card that support each electrical interface: the electrical interface designations (V.35, RS422, and X.21) are silk-screened on the back of the card.

On the FRAM-01 data card, there are three connectors on the component side of the board (corresponding to the three data channels) where the interface adapter card can be installed. (See ) The connector closest to the J2 jumper and LED supports data channel 1. The connector in the middle supports data channel 2. The connector closest to the 68-pin connector supports data channel 3. To install an interface adapter card, simply choose the appropriate electrical interface connector (V.35, RS422, or X.21) on the interface adapter card and plug it into one of the data channel connectors on the FRAM-01 data card.

FRAM-01 Interface Adaptor Card

The default interface for each port is RS-232. The interface adaptor card enables each port to present an RS-422, V.35, or X.21 interface, as selected by the position of the interface adaptor card.

FRAM-01 Jumpers

There are several jumpers on the FRAM-01 card. They are all set at the factory and cannot be changed.

Telephony Interface

Voice Fax Expansion Modules provide support for three different types of telephone interfaces: FXS, FXO and E&M.

FXS Connections

FXS is a two-wire telephone communication mode. In this mode, the Voice Fax Expansion Modules present a telco/PTT interface similar to a Central Office interface. When configured in this mode, a Voice Fax Expansion Module can interface to a conventional two-wire telephone (pulse-dial or touch-tone). A Voice Fax Expansion Module in FXS mode can also be connected to a two-wire CO trunk of a PBX or KSU. Additionally, in FXS mode, the Voice Fax Expansion Module provides loop current similar to a telephone company's Central Office. It also detects off-hook and on-hook states, and generates ring voltage.

FXO Connections

FXO is a two-wire telephone communication mode. In this mode, the VFC-01 or VFC-03 presents a telco/PTT interface which looks like a standard telephone set. The VFC card can be connected to analog station ports (extensions) of a PBX. The FXO option provides the appearance of a two-wire telephone in a loop-start circuit. An FXO-configured voice port on the VFC card detects ring voltage and closes the loop during off-hook and opens the loop in an on-hook condition.

When a Voice Fax Expansion Module is used in two-wire mode, set all four switch positions of the DIP switch pack (Switch 2) located on the rear Voice Fax Expansion Module to the UP position (away from board). This applies to both FXO or FXS operation.

E&M Connections

E&M is a communication mode employed in PBX-to-PBX communications. This type of interface uses a two-wire or four-wire voice circuit plus up to four wires for E&M signalling.

PBX E&M tie-line connections usually require multi-conductor dedicated circuits to support full-duplex voice and separate signalling lines. Typically, eight wires are required: four for voice (two wires in each direction) and four for E&M signalling. Some PBXs use two wires (one pair) for bi-directional voice. Voice Fax Expansion Modules can interface with either type of circuit.

This section provides configuration information required to interconnect the port configured for E&M signalling with a corresponding PBX E&M tie line trunk. Appendix G, , provides additional information concerning E&M signalling types.

Note

The FastPAD supports PBX-to-PBX communications only when the PBXs are configured for immediate start.

Switch 1 on the VFC-01 card in the E&M position (toward the rear of the card), selects E&M signalling. E&M is software selectable from the front panel on VFC-03 boards. The DIP switch pack (Switch 2) on the rear of the Module must then be used to select the type of E&M signalling (I through V).

E&M signalling requires the use of the RJ45 connector. Both two-wire and four-wire E&M interfaces are supported; this selection is made via the front panel expansion channel configuration.

Table 7-3 E&M Signalling Types (Switch 2) Settings (facing rear of installed card)


E&M Type	SW1	SW2	SW3	SW4
I	Right	Right	Left	Left
II	Left	Right	Right	Left
III	Right	Right	Right	Left
IV	Left	Right	Right	Left
V	Down	Up	Down	Down
FXO	Left	Left	Left	Left
FXS	Left	Left	Left	Left

Follow this step-by-step check list when connecting the Voice Fax Expansion Module in an E&M application:

Step 1

Determine the required E&M signalling convention used by the PBX tie line port: Type I, II, III, IV, or V.

Step 2

Set the DIP switches, accessible from the rear of the Voice Fax Expansion Module, for the proper signalling type. Switch 2 DIP switch settings are defined in .

Step 3

Connect the voice pair(s) and signalling wires as outlined in the section "E&M Wiring" in this chapter.

Step 4

Finally, configure each Voice Fax Expansion Module channel parameter to reflect the hardware configuration. Configuration instructions are found starting in Chapter 9 of this manual.

Note

Normally, when PBX-to-PBX E&M tie trunks are installed, the E lead of one PBX is crossed over and connected to the M lead of the other PBX, and vice versa. In a multiplexer application the crossover is accomplished digitally, therefore, when connecting a PBX to a FastPAD in E&M mode, the E and M leads of the PBX connect to the E and M leads of the FastPAD straight through, without crossing.

Grounding Considerations in E&M Applications

Proper grounding is essential for correct operation of telephone equipment in E&M applications. E&M signalling works by applying DC voltages to the E and M leads in the process of connecting and disconnecting. Without a proper ground, the DC voltages do not have a common point of reference, which can result in unintended or sporadic signalling.

If the PBX and the FastPAD are not within close proximity, then their AC grounds may not be the same. If the FastPAD and the PBX are in the same room, however, it is likely that they share the same AC ground.

In an E&M application, the common ground must also be the telco/PTT ground. This assures that the ground potential of the PBX telephone interface and the FastPAD telephone interface are the same.

Based on the above conditions, grounding may be established directly or indirectly. The direct method is to connect a grounding wire between the telco/PTT interfaces on the PBX and FastPAD. You can do this by connecting the ground wire from the PBX to pin 8 (SG) of the RJ45 connector on the Voice Fax Expansion Module. This will establish the same ground potential at both interfaces.

For various reasons, direct grounding is not always possible or practical. To establish an indirect ground, make sure the telco/PTT grounds of the PBX and the FastPAD are connected to their respective AC grounds. The AC grounds of the two devices must be at the same potential as is usually true when both devices are located in close proximity.

Check with the PBX manufacturer regarding connecting the PBX AC ground to telco/PTT ground. On the FastPAD, installing a jumper at W7 on the baseboard provides the connection between chassis ground (same potential as AC ground) and telco/PTT ground. A common telco/PTT ground will then be present for every expansion module installed in the FastPAD. Jumper location W7 can be found on the baseboard next to the power supply cage, near the front of the FastPAD.

Note

Connecting AC grounds and telco/PTT grounds of telephone equipment may violate rules of certain regulatory agencies. Please check with your local telephone company and/or agency regarding regulations that deal with grounding.

Interface Conversions

The FastPAD allows you to use a different telephony interface at either end of a voice/fax connection. Through system software, each Module is informed of the interface type used at the remote end. Signaling conversion is done in software without the aid of any external equipment.


1.	E&M	to E&M
2.	E&M	to FXS Loop Start
3.	E&M	to FXO Loop Start/Ground Start
4.	FXS	Loop Start to FXS Loop Start
5.	FXS	Loop Start to FXO Loop Start/Ground Start
6.	FXS	Ground Start to FXS Ground Start

Installation Instructions

The FastPAD must be unplugged from the AC power source before you remove the protective cover. Proper anti-static procedures must be followed.

A VFC expansion module can be installed in any available expansion slot in a FastPAD or FastPAD Micro. Complete the following steps to install a VFC expansion module:

Step 3

Turn the power switch to OFF and unplug the unit from the AC or DC power source.

Step 5

Determine the expansion module slot where the module will be installed and remove the filler panel from the back panel of the unit.

Step 6

Place the expansion module into the selected slot and align the edge connector of the card with the expansion slot connector.

Step 8

Install the screw with lock washer on the connector edge of the card to secure it in place.

PTT/Telco Connectors and Cabling

The 8-wire RJ45 jack on a Voice Fax Expansion Module is mainly used for E&M operation.

An RJ45 cable is included with each Voice Fax Expansion Module. The cable end with the RJ45 connector plugs into the Module. The cable end with non terminated wire connects to a telco/PTT type spay lug block.


PinNo.	Color	Usage	Description
1	Gray	SB	Return for M Signal
2	Orange	M	Control Signal from PBX
3	Black	TR	Voice from PBX (Transmit Ring)
4	Red	RR	Voice to PBX (Receive Ring) two-wire connection
5	Green	RT	Voice to PBX (Receive Tip) two-wire connection
6	Yellow	TT	Voice from PBX (Transmit Tip)
7	Blue	E	Control Signal to PBX
8	Brown	SG	Return for E Signal

The 6-wire RJ11 jack on the Voice Fax Expansion Module is connected in parallel with the RJ45 jack. However, the RJ11 only supports two pins: Tip (green) and Ring (red). A standard RJ11 two-wire cable is included for establishing two-wire connections.

The supplied RJ45 cable can also be used to provide the two-wire connection. For these applications, only the red and green wires are active; the other wires should be insulated with electrical tape to prevent unwanted interference.

E&M Wiring

In a two-wire E&M application, connect Red and Green wires to the PBX's RT and RR pair, respectively. The RT and RR pair carry voice or fax analog signals between the Voice Fax Expansion Module and the PBX.

In a four-wire E&M application, connect Red and Green wires to the PBX's RT and RR pair, and Black and Yellow wires to the PBX's TR and TT pair, respectively. The RT and RR pair carry voice or fax analog signals from the Voice Fax Expansion Module to the PBX. The TR and TT pair carry voice or fax analog signals from the PBX E&M tie trunk to the Voice Fax Expansion Module. Connect the signalling wires as shown in .


Signalling Type	Connections
I, V	Connect Blue wire to the E, Orange wire to the M and Brown wires to the SG (or common ground) PBX leads.
II, IV	Connect Blue wire to the E, Brown wire to the SG, Orange wire to the M and Gray wires to the SB PBX leads.
III	Connect Blue wire to the E, Orange wire to the M and Gray wire to the SB PBX leads. Connect Brown wire to SG or common ground.

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