Schneider Electric TAC Xenta 421A, TAC Xenta 422A Installation Instructions

TAC Xenta® 421A/422A

02-00002-01-en

Universal Input and Digi­tal Output Module

LONMARK CONFIGURATION AND VARIABLES

Physical Inputs and Outputs

TAC Xenta 421A/422A can be used as a normal Xenta I/O
module or as a certifi ed L

• 4 Universal Inputs (UI)

• 5 Digital Outputs (DO)

In addition, TAC Xenta 422A has fi ve manual switches, one for
each DO that can be set

• manual Off

• manual On

• Auto

To confi gure the inputs and outputs, and to specify the trans­mission of values, either ordinary TAC Menta®/Xenta confi gu­ration or nci SNVTs are used. The usage is explained overleaf
("SNVT vs TAC Xenta I/O module Communication".)

The use of SNVTs requires explicit information listed below.

UI Confi guration

Each of the four UI:s (1-4) is confi gured with

nciInput1-4 0 = not connected (default value)
1 = 1.8 kohm thermistor
2 = DI, green indication
3 = 0-10 V
4 = 0-20 mA
5 = 10 kohm thermistor
6 = DI, red indication
7 = DI, green inverted indication
8 = DI, red inverted indication

ONMARK® device. It has

Off: state=0, value=0
On: state=1, value=100
Invalid: state=255

nvoTemp1-4 (thermistor, any type; invalid=327.67)

UI Value Transmission

The UI value will be transmitted

a) when the change in value is large enough (set individually

b) at a specifi ed time interval (common for all UIs)

a) is determined by

nciSndDelta1-4 (dimensionless; default value=2)
Size of change to cause transmission
Ex.: 1 means

- if confi gured as analog input: 1%

- if confi gured as temperature input: 1 °

If the UI is confi gured as a digital input, a status change will
always be transmitted.

b) is determined by

nciSndHrtBt "Heartbeat" interval in seconds (default=60)

A valid and confi gured UI value will be sent at least once dur­ing each interval regardless of change.

The transmissions will be distributed over time to avoid mo­mentary communication overload.

Confi guration Instruction

per UI)

DO Values

If confi gured to be a digital input (DI, any type), its function is
further determined by the corresponding bit in

nciDigInNONC:

If bit=0: NO, normally open (default value)

If bit=1: NC, normally closed

Pulse counting is not available for SNVT communication.

UI Values

Depending on the UI confi guration, each UI n=1-4 generates
a valid value in one of these (the other two are set invalid):

nvoAnalog1-4 (0-10 V or 0-20 mA, converted to 0-100%;
invalid=163.835)

nvoDigital1-4 (DI, any type)

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Bit 0 Bit 15

DI 1
DI 2
DI 3
DI 4

The digital output values to the output (DO, n=1-5) are re­ceived as:

nviDO1-5 switch:state
state=0 or >1: Off
state=1: On

For the TAC Xenta 422A, the DO values may be overridden by
manual switches. Their status is indicated in

nvoHandBoard1-5 switch:state.
state=0: manual Off
state=1: manual On
state=255 ('invalid'): Auto

Any DO status change will immediately be transmitted.

DO Values in the Off-line Condition

The DO values are expected to be updated regularly. How­ever, this may be prevented by communication failure or, tem­porarily, after power-up.

(continued ...)

To determine if all nviDO1-5 are to be considered valid, an
interval counter is used:

nciRcvHrtBt No. of seconds until nviDO1-5 are consid-

If bit=1: Use default value as specifi ed by

nciOffl ineVal, using the following bits, where the value to be
used is specifi ed (0 or 1). (Default value=0.)

ered invalid. (0: function is not used; default value.)

If this happens, due to communication failure, the behavior is
determined by

nciOffl ineBeh, using the following bits:

Bit 0 Bit 15

DO 1
DO 2
DO 3
DO 4
DO 5

If bit=0: Keep latest value (default).

SNVT vs TAC XENTA I/O MODULE COMMUNICATION

Bit 0 Bit 15

DO 1
DO 2
DO 3
DO 4
DO 5

The TAC Xenta 421A/422A can be used in networks with
either LONMARK communication or TAC Xenta I/O module com­munication. The device automatically determines which type
of communication to use.

Green

Power-up

SNVT

received

Green blink
at comm.
or 0.1 Hz

In the Power-up state, the green LED blinks "Off-line". The

State diagram

SNVT

TAC Xenta
I/O module
comm.
established

off-line
blink

TAC Xenta I/O module
communication
established

TAC Xenta
I/O module

communication

I/O on-line:
green 0.5 Hz

device is open for both SNVT and TAC Xenta I/O module
communi cation.

Previous confi guration, if defi ned, will apply until a change is
initiated.

SNVT received

The device enters the SNVT state. The device is confi gured
when the nci:s are updated. The green LED will light up when
there is communication or approximately every 10 seconds.

SNVT transmission is determined by the nciSndDelta1-4 or
the nciSndHrtBt values.

The device remains in the SNVT state until a TAC Xenta I/O
module communication state is established, or until the next
power-up. In the SNVT state it is possible to change the con­fi guration by updating the network confi guration inputs nci:s.

TAC Xenta I/O module Communication

The TAC Xenta I/O module communication state is accepted
only after a thorough protocol initiation. This may be initiated
at any time.

In the TAC Xenta I/O module communication state, no nvi:s
or nci:s can be used. The green LED blinks on-line at about

0.5 Hz.

Input SNVTs are ignored, also when the device is off-line from
the controller.

However, output SNVT transmission is still performed using a
hard-coded interval of about 10 seconds.

Once in the TAC Xenta I/O module communication state, the
device can only enter the SNVT state after a new Power-up. At
this stage all nci:s must be updated, since the same memory
area is used by both the SNVT and TAC Xenta I/O module
communication confi guration parameters.

Note! As the TAC Xenta I/O module communication state is
a 'dead-end' (until power-up), any mis-addressed communi­cation may cause the I/O module to loose its SNVT communi­cation state.

TAC Xenta I/O module communication is inititiated by the con­troller at events specifi ed below. If an I/O module intended for
SNVT communication has been used in another confi guration
and happens to have an address that is used by the I/O mod­ule communication, the I/O module will be 'lost' in this state.

TAC Xenta I/O module communications will be initiated by the
following events:

• Controller power-up

• I/O module power-up

• Controller application download

• Recovery after communication failure

Service pin

Red LED (Confi guration error)

- blinking: unconfi gured node

- steady: appl.less (or hw fault)

Green LED (Communication)

- SNVT: at communication or ~ once in 10 sec.s

- TAC Xenta I/O mod communication:
on-line ~ every other sec; off-line ~ 5 blinks per sec

LED indicators on front panel

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