Incon 1250-LTC Installation And Programming Manual

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INSTALLATION AND

PROGRAMMING MANUAL

FOR MODEL

1250-LTC

PROGRAMMABLE POSITION MONITOR

Solid State Indicator for SynchroTransmitter

000-2072 Rev. C

INTELLIGENT CONTROLS, INC.

PO Box 638

Saco, Maine 04072 USA

Phone: 207-283-0156 FAX: 207-283-0158

Toll Free: Technical Service & Sales 800-872-3455

Web Site: www.incon.com E-mail: sales@incon.com

This manual applies to all INCON model 1250-LTC monitors

TABLE OF CONTENTS

Section: Page:

List of Figures…………………………………………………………………… 4

List of Tables……………..……………………………………………………… 4

Introduction……………………………………………………………………... 5

1.0 Installation……………………………………………………………..…… 5 - 8

2.0 Programming…………………………………………………………..…… 9 – 33

2.1 Front Panel Programming…………………………………………….. 9

2.2 Serial Port Programming – ASCII …………………………………… 13 - 17

2.3 Serial Port Programming – MODBUS……………………………….. 18 – 33

2.3.1 MODBUS Packet Format – Read……………………………….. 19

2.3.2 MODBUS Packet Format – Write………………………………. 20

2.3.3 MODBUS Packet Format – Error Exception Response……….. 21

2.4 Operating Modes………………………………………………………. 34 – 37

2.5 Programming Notes……………………………………………………. 38

3.0 Options…………………………………………………………………..….. 39 – 48

3.1 Analog Output……………………………………………………..…… 39

3.2 High / Low Relay Limits………………………………………..……… 40 – 45

3.2.1 Tap Change Acknowledgement.………………………………… 41

3.2.2 High Tap / Low Tap……………………………………………… 41

3.2.3 Total Tap Change Count………………………………………… 42

3.2.4 On-Tap Alarm……………………………………………………. 42

3.2.5 Up-To & Down-To Count………………………………….…….. 44

3.2.6 Pass-Through-Neutral Alarm…………………………….……… 44

3.2.7 One-Direction Change Count…………………………….……… 45

3.2.8 FA 25 & FA 27 Error Alarm…………………….…………….… 45

3.3 Serial RS-232…………………………………………………...……….. 46

3.4 Serial RS-485 .……………………………………...………………….... 47

3.5 Input Isolation…………………………………………………...……… 48

4.0 Field Calibration and Test………………………………………...…….…. 48 – 49

5.0 Error Codes…………………………………………………………….……. 50

6.0 Specifications…………………………………………………………….….. 51

LIST OF FIGURES

Figure: Page:

1.1 Mechanical Dimensions…………………………………………………………… 6

1.2 Field Wiring Diagram…………………………………………………………….. 6

1.3 Field Wiring Diagram with 4-20mA Option.…………………………………….. 7

2.1 Simplified Programming Flowchart…...…………………………………………. 12

2.2 Serial Data Dump Example……………………………………………………….. 17

2.3 Base 1 Uni-Polar Mode Analog Output………………………………………….. 35

2.4 Base 0 Uni-Polar Mode Analog Output………………………………………….. 36

2.5 Bi-Polar Mode Analog Output…………………………………………………… 37

3.1 Relay Field Wiring Diagram……………………………………………………... 40

3.2 On-Tap Example………………………………………………………………….. 43

4.1 Analog Output Adjustment Pots…………………………………………………. 49

LIST OF TABLES

Table: Page:

1.1 Terminal Functions……………………………………………………………… 7

1.2 DIP Switch Functions…………………………………………………………... 7

1.3 Analog Output Configuration Jumpers…………………………………………. 8

2.1 Numeric and Alpha-numeric Menu Items……………………………………… 9-12

2.2 Serial Programming ASCII Commands……………………………………….. 13-15

2.3 Read Registers Command Format..……………………………………………. 19

2.4 Read Registers Response Format.…………………………..………………….. 19

2.5 Write Registers Command Format……………………………………………... 20

2.6 Write Registers Response Format……………………………………………… 20

2.7 Error Exception Response Format……………………………………….…….. 21

2.8 RS-485 MODBUS Register Definitions...……………………………………… 22-33

3.1 Analog Output Load Limits……………………………………………………. 39

3.8 Wiring: Digital Connector Pin-Out……………………………………….…….. 47

5.1 Error Codes …………………………………………………………….….……. 50

INTRODUCTION

The Model 1250-LTC Programmable Position Monitor is a highly advanced solidstate instrument, which measures the absolute position of a synchro transmitter. It provides both a user definable visual panel indication and optional analog and digital signal outputs suitable for a variety of monitoring and control applications.

The INCON 1250-LTC series is unique in its capability to monitor up to 40 userdefinable position segments. It is specifically designed for monitoring power transformer load tap changer position, where the desired readout is in whole tap numbers. Its transmitter can be attached to any operating shaft on the LTC and the 1250 programmed to read out in tap positions. The display and all outputs follow a “stair step” function defined in the program. The INCON 1250 has become the industry standard for LTC position monitoring.

In addition to basic LTC tap position, the 1250-LTC can provide useful information about the movement of the LTC. Beginning with a momentary (optional) relay closure after each successful tap change, the 1250-LTC keeps records on seven important issues relating to LTC movement, including: total number of tap changes; number of days since last “pass through neutral”; number of changes “up to” and “down to” each tap; and more.

Most LTC’s rotate about 9 to 11 degrees with each tap change. The 1250-LTC can measure in increments of 1/10th of a degree. A special feature of the 1250-LTC is its ability to monitor small discrepancies in tap position. A programmable limit can be set to give an alarm when the discrepancy in tap position reaches the limit. Inaccurate tap position can be an early indicator of wear in the LTC mechanism or possible impending failure.

The 1250-LTC may be wired in parallel with existing synchro transmitter/receiver pairs or wired directly to the synchro transmitter. Additional 1250’s may be wired to the same transmitter without compromising the accuracy or reliability of the system.

1.0 INSTALLATION

• The Model 1250-LTC is designed for use in any 50/60 Hz, five-wire synchro system compatible with electrical specifications given in Section 6.0, page 51. These devices include CX, TX, CDX, and TDX function synchros, as well as Self-Synchronous Indicator devices. (INCON’s model 1292 Synchro is a highly specified robust transmitter with a history of proven performance.)

• The panel-mount case is designed to snap-fit into a standard 1/8 DIN rectangular cut-out of 44mm (1.73 in.) by 92mm (3.62 in.)

• Wiring is done to the rear of the case. #16 AWG (min.) type THHN, THWN, TFFN, or equivalent wire is recommended for the five AC synchro lines. #20 AWG (min.) shielded twisted pair wire is recommended for analog output wiring. Use appropriate spade lugs (provided) when connecting to the case terminals.

• Contact INCON Technical Service (1-800-872-3455) for application assistance if the synchro transmitter and the 1250-LTC monitor are separated by a wire run of more than 1200 feet.

Figure 1.1 Mechanical Dimensions

Figure 1.2 Field Wiring Diagram

Figure 1.3 Field Wiring Diagram with 4-20mA Output

Table 1.1 Terminal Functions

Terminal Function Terminal Function

A S1 1 Analog Output + B S2 2 Analog Output – C S3 3 Program Mode Inhibit D (Spare) 4 Inhibit Return E R1 * 5 Line L1 * F R2 * 6 Line L2 * 7 Chassis Ground * Terminals E & F are 8 Relay Low Contact N.O. jumpered to 5 & 6 9 Relay Common respectively 10 Relay High Contact N.O.

A DIP switch tells the firmware which hardware options are installed, so their function can be enabled. It is located on the top PCB, above the power transformer and is accessible through a slot in the left side of the case, towards the rear of the instrument.

Table 1.2 DIP Switch Functions

Switch # Function

1 Serial Communications Option Enable 2 MODBUS Protocol Enable 3 Spare 4 High / Low Relay Limit Option Enable 5 Analog Output Option Enable 6 Spare 7 Spare 8 In-Factory Test & Calibration Menu Enable

Installation Notes:

1) A resistor may be wired remotely across the analog output terminals to convert analog output milliamp current to a voltage. Use Ohm’s Law to calculate the proper resistance for the desired voltage based upon the 1250-LTC’s rated output current.

2) Maximum analog output load resistance: 0-1mA = 10K ohms; +/-1mA = 10K ohms; 0-2mA = 5K ohms; 4-20mA = 500 ohms.

3) Models with 4-20 mA analog output options must have an EXTERNAL LOOP POWER SOURCE of 10.0 VDC minimum, 24.0 VDC maximum, in series with the current loop. The INCON Model 1945 Power Supply is recommended for these installations, (See Figure 1.3, page 7).

4) When additional remote indication is needed, several 1250-LTC’s may be wired in parallel to the same transmitter. The 1250-LTC can also be connected via its serial port to the INCON model RD-4 Remote Display unit.

5) The 1250-LTC and the synchro transmitter MUST BE WIRED TO THE SAME AC SOURCE. Do not remove the jumpers from terminals E and F.

6) A wire jumper or keyswitch may be installed between terminals 3 & 4 to prevent the program from being changed. When these terminals are jumpered the menu will read “EP-x” instead of “OP-x”, which indicates that you can Examine each Parameter, but not change them.

7) After installation and programming, install the rear terminal guard with screws provided.

8) For models with serial options, plug the cable onto the card edge with the red stripe towards the outside of the case.

Application Bulletins:

1) If there is a large component of AC “ripple” present on the 1250 analog output, check the isolation of all wiring with respect to earth ground. R1, R2, S1, S2, and S3 should measure infinite resistance to earth ground. In applications where external isolation is not sufficient, the Input Isolation Option (-I) is required to break the ground path that causes this ripple. See Application Bulletin #000-1150 for more detailed information.

2) Analog outputs of 0-1mA, +/-1mA, and 0-2mA can be changed in the field to any one of the other two (see Table 1.3). The configuration jumpers are located on the bottom PCB. See Application Bulletin #000-1151 for more detailed information.

Table 1.3 Analog Output Configuration Jumpers

Output Signal: J8 J10 J12 J13

0-1mA Jumped Jumped Jumped

+/-1mA Jumped Jumped Jumped

0-2mA Jumped Jumped

2.0 PROGRAMMING

The Model 1250-LTC has three methods of programming: numeric menu (traditional

1250); alphanumeric menu; and serial port programming commands. The 1250-LTC can be

ordered with either RS-232 or RS-485 serial port hardware. The serial programming commands can be in the form of ASCII characters or MODBUS packets, depending upon the position of DIP switch #2. See Tables 2.1, 2.2 & 2.3 for a full listing of all programming menu items, commands, and syntax. See the simplified programming flowchart for tap position on page 12, Figure 2.1.

2.1 Front Panel Programming

To access the numeric or alphanumeric programming menu, press the MENU key for several seconds until the display goes blank, then press the SELECT/ENTER key. The display should read “OP 0”. The default menu is the numeric menu. To choose the alphanumeric menu, press the DOWN key to select OP 99. Press the SELECT/ENTER key, the display should read “to OP”. Press the UP key. The display should read “run”. You are now in the alphanumeric menu mode.

To change a parameter using the numeric or alphanumeric menus, select the parameter to be changed from the menu, press the SELECT/ENTER key. The parameter’s present setting will now be displayed. You can change the setting by pressing the UP or DOWN key. To store the new setting, press the SELECT/ENTER key, the display will return to the menu.

Table 2.1 Numeric and Alphanumeric Menu Items:

Numeric

OP 0 run Press the SELECT/ENTER key to exit the

OP 2 Func Select Operating Mode (see pages 34-37) 21 16, 17, 18, 19, 20,

OP 3 tCrLY Selects which relay will assert

OP 4 tCrdL Sets the delay time before Tap Change

OP 5 tCrLt Sets duration of time the Tap Change

OP 6 dHF-L Selects which visit to the Draghand

OP 10 LtCLr Low Tap Alarm Clear CL OP 11 HtCLr High Tap Alarm Clear CL OP 15 rL Lt Sets low relay limit tap -16 Any valid tap

OP 16

OP 17 rL Ht Sets high relay limit tap +16 Any valid tap

OP 18

Alpha-numeric Protocol

LtrLY

HtrLY

Function: Default

Value:

Program mode

OFF OFF, LO, HI

momentarily, after each tap change

0.0 0.0 to 9.9

Acknowledge Relay turns on (Seconds)

0.0 0.0 to 9.9

Acknowledge Relay stays on (Seconds)

LASt “FirSt”, “LASt” positions (first the day counters

Selects which relay will assert when the “Low Tap” alarm limit is reached

Selects which relay will assert when the “High Tap” alarm limit is reached

time or last time) will begin

OFF OFF, LO, HI

Programmable Range:

number

Numeric

OP 19

OP 20 OP 21 OP 22 nEu Number of neutral taps 1 0 to 8 OP 23 n St Sets lowest neutral tap 0-1 Any valid tap

OP 27 S Pt Sets present tap position 0 Any valid tap

OP 28 L Pt Loads present tap position into memory Ld OP 29 dSPrL Enables display of “r” or “L” in Function

OP 30 CAL E Enables analog output Calibration Mode OFF On or OFF OP 31 L CAL Forces the analog output to its lowest

OP 32 H CAL Forces the analog output to its high scale

OP 33 d CAL Forces the analog output to its mid scale

OP 34 t CAL Forces the analog output to alternate

OP 39 dOG t Forces a Watchdog Reset (Factory use

OP 40 LED t Display LED Test: Turns on all LED’s -8.8.8.8.8. OP 41 rS t RS-232 Echo Test: Re-transmits characters

OP 42 InCAL Calibrates synchro input circuitry CAL OP 43 rLY t Relay Test: UP and DOWN keys toggle

OP 50 dSPbL Causes the display to go blank after 60 sec. OFF On or OFF OP 51 SEr Serial Communication Mode:

OP 53 Aut25 Auto-Reset after “FA 25” Loss of Synchro

OP 54

OP 55 ttCLt Sets Total Tap Change counter alarm limit

OP 56 ttrLY Selects which relay will assert when the

OP 57 ttPrE Presets the Total Tap Change counter in

OP 58 ttdtE Total Tap Change counter reference date

OP 59 ttCdS Displays Total Tap Change Count and

Alpha-numeric Protocol

dEGrE

tAPS d SEG

25rLY

Function: Default

Value:

Displays absolute synchro position in degrees with one decimal place resolution Number of taps 33 2 to 40 Degrees per tap 10.000 -99999 to +99999

Modes 20 and 21

signal output

signal outputs

between high and low scale signal outputs

only)

received through the RS-232 serial port

between LO and HI relays

0=Serial Disabled, 1=Data Logger Mode, 2=Polled Mode, 3=Sampled Mode, 4=Serial Command Mode, 5=Reserved, 6= MODBUS Mode, 7=Remote Display Driver Mode

Signal Error (page 50) Selects which relay will assert when the “FA 25” error is active

in THOUSANDS

Total Tap Change counter limit is reached

THOUSANDS

Enter day, month, year

reference date Press ENTER to exit

OFF On or OFF

- -

LO then HI

<<Press ENTER>>

LO then HI

0 0 to 4, and 6

OFF On or OFF

OFF OFF, LO, HI

000.01 000.01 to 999.99

OFF OFF, LO, HI

000.00 000.00 to 999.99

01–01–00

Programmable Range:

number

Numeric

OP 60 Aut27 Auto-Reset after “FA 27” Unstable

OP 61

OP 62 OtGLt Sets On-Tap guard band limit (Degrees) 0.1 0.1 to 9999.9 OP 63 OtrLY Selects which relay will assert when the

OP 64 OtdtE On-Tap reference date

OP 65 OtdIS Scrolls through the list of taps, to select,

OP 66 Otdtd Scrolls through the list of taps which have

OP 67 OtCLr Clears the On-Tap alarm CL OP 68 OtrSt Resets all On-Tap logs & alarm rESEt OP 70 udCLt Sets the alarm limit for the number of

OP 71 udrLY Selects which relay will assert when the

OP 72 uddtE UP TO & DOWN TO Change counter

OP 73 uddIS Scrolls through the list of taps to select,

OP 74 udCLr Clears an active Up-To and Down-To

OP 75 udrSt Resets all Change Up-To and Down-To

OP 80 POrt Sets serial port parameters: (press the UP

OP 85 PtnLt Sets the limit for number of days without a

OP 86 PtrLY Selects which relay will assert when the

OP 87 PtdIS Displays the number of days since the last

Alpha-numeric Protocol

27rLY

Function: Default

Value:

OFF On or OFF Synchro Signal Error (page 50) Selects which relay will assert when the “FA 27” error is active

On-Tap guard band limit is reached

Enter day, month, year

Press ENTER to display the highest measured deviation, for that tap Press MENU to escape back to the menu

exceeded the On-Tap alarm limit to select, Press ENTER to display the highest measured deviation, for that tap Press MENU to escape back to the menu

changes UP TO any tap in THOUSANDS

“UP TO” change alarm limit is reached

reference date Enter day, month, year

Press ENTER to display the Change UpTo count Press ENTER to display the Change Down-To count, for that tap Press MENU to escape back to the menu

Change alarm

counters and alarm

or Down key to select a value, press the enter key to move to the next parameter)

Baud rate

Word length

Parity (n=none, E=even, O=odd)

Stop bits

Address (for RS-485 Multi-drop)

“Pass Thru Neutral”

“Pass Thru Neutral” time limit is reached

“Pass-Through-Neutral”

OFF OFF, LO, HI

01–01–00

Any valid tap

000.01 000.01 to 999.99

OFF OFF, LO, HI

01–01–00

0 Any valid tap

rESEt

9600

128

OFF Off, 0.1 to 365.0

OFF OFF, LO, HI

Programmable Range:

number

2400, 4800, 9600, 14400, 19200, 28800,38400, 57600, 76800

7 or 8 n, E, O 1 or 2 0 to 255

Numeric

OP 88 PtrSt Resets the “Pass-Through-Neutral”

OP 90 1dCLt Sets the limit for number of consecutive

OP 91 1drLY Selects which relay will assert when the

OP 92 1ddIS Displays the number of days since the

OP 93 1dCLr Clears “One Direction Change” alarm CL OP 99 tO OP Toggles between Numeric and

Alpha-numeric Protocol

Function: Default

Value:

rESEt counter & alarm

2 2 to 30 tap changes in One Direction

OFF OFF, LO, HI “One Direction Change” limit is reached

“One Direction Alarm” was asserted

tO OP Alphanumeric menus

Programmable Range:

Figure 2.1 Simplified Programming Flowchart

2.2 Serial Port Programming - ASCII:

These commands require either the RS-232 (-S) or RS-485 (-M) hardware option. To use the serial port programming commands, connect a computer terminal to the serial port cable. The terminal must have the proper Comm port settings to communicate to the 1250-LTC (see Sections

3.3 and 3.4, pages 46 - 47). See Table 2.2 for a full listing of all Serial Programming Commands and syntax. At the command prompt, type a command followed by the new parameter setting, using proper syntax as shown in Table 2.2. Typing the command only, without a new para-

meter setting, will cause the 1250-LTC to transmit the present setting for that parameter.

Table 2.2 Serial Programming ASCII Commands:

◊=space ª=enter

Command Syntax: Function: Explanation:

SETUPª Enter the Setup Mode This command must be entered before

any other commands can be made.

EXITª Re-starts the serial connection Changes to comm. port settings will take

effect

RUNª Return to the Run Mode Changes to settings will take effect DISPª Displays all setup parameters Each setup parameter command is dis-

played with the current value following it

DUMPª Displays all measured LTC

information

(See Figure 2.2, page 17)

POSª Displays present Tap #, synchro

position (in degrees) and current On-Tap deviation degrees

MODE◊nnª ACKRLY◊LOª

ACKDLY◊nn.nª

ACKHOLD◊nn.nª

DHCOUNT◊FIRSTª

DHLRST Low Draghand Reset Draghand value becomes present tap DHHRST High Draghand Reset Draghand value becomes present tap LTLMT◊nnª LTRLY◊LOª

LTCLRª Clears Low Tap Alarm Also resets “Days Since Alarm” counter HTLMT◊nnª HTRLY◊LOª

HTCLRª Clears High Tap Alarm Also resets “Days Since Alarm” counter TAPS◊nnª

Segmented modes See Section 2.4, page 34-37 for details Selects which relay will assert

momentarily after each tap change Sets the delay time, in seconds, before the ACK relay asserts Sets the duration, in seconds, that the ACK relay remains on Selects which visit to the Draghand position to begins the day counter

Set Low Tap alarm limit n= an integer, any valid tap number Selects which relay is associated

with the Low Tap alarm

Set High Tap alarm limit n= an integer, any valid tap number Selects which relay is associated

with the High Tap alarm

Set number of taps n= an integer from 2 to 40

Lists: Total tap change count, Days since Pass-Through-Neutral, High & Low Draghand positions, Change Up-To and Down-To counts for each tap, Maximum On-Tap deviations for each tap, etc… Reads Tap #, 0.0 to 359.9 degrees, with one decimal place of resolution Press ª (enter) to exit

Choose “OFF”, “LO” or “HI” relay to assert momentarily after each tap change

n= a number from 0.1 to 9.9 with one decimal place resolution n= a number from 0.1 to 9.9 with one decimal place resolution Choose “FIRST” or “LAST” visit. The number of days since the LTC visited that extreme position the first or last time

Choose “OFF”, “LO” or “HI” relay to assert when the alarm limit is reached

Command Syntax: Function: Explanation:

DEGSEG◊n.nnnnª

NEUTRALS◊nª NSTART◊nnª SETTAP◊nnª LDTAPª DISPRL◊ONª

ANACALª

WDOGTESTª LEDTESTª Turns on all display segments Press the enter key to stop the LED test INCALª Self-calibrates the input circuitry Outputs “Pass” or “Fail” calibration

RLYTESTª Forces Hi / Lo relay output to

DSPBL◊ONª

SERIAL◊nª

AUTO25◊ONª

FA25RLY◊LOª

RESET25ª Manually clears the “FA 25”

TTCLMT◊nnn.nnª

TTCRLY◊LOª

TTCPRE◊nnn.nnª

TTCDATE◊mm-dd-yyyyª

AUTO27◊ONª

FA27RLY◊LOª

RESET27ª Manually clears the “FA 27”

Set degrees per segment n= a floating point number, 5 digits max,

average number of degrees between taps Set number of neutral taps n= an integer from 0 to 8 Set lowest neutral tap number n= an integer, any valid tap number Set present tap position n= an integer, any valid tap number

Load present tap pos. into memory Enables the display of “r” (raised)

and “L” (lowered) tap numbers

Must be done for SETTAP to take effect

“ON” or “OFF” When enabled causes

the display to show “r” and “L” in

function modes 20 and 21 only

Enter analog calibration mode, the 1250 analog output will be forced to Low / Mid / High signal output Forces a Watchdog Reset This command is for factory use only.

Press the space bar to toggle between

Low / Mid / High analog output. Press the

enter key to stop calibration

result

Press the Space Bar to toggle between close Enables the display blanking feature

Lo or Hi relay Press ª (enter) to exit

“ON” or “OFF” When enabled causes

the display to go blank after 60 sec. Set serial communication mode 0=Serial Disabled, 1=Data Logger

Mode, 2=Polled Mode,

3=Sampled Mode,

4=Serial Command Mode, 5= Reserved,

6=MODBUS Mode, 7=Remote Display

Driver

Enables automatic reset of the “FA 25” Loss of Synchro Signal Error (page 50) Selects which relay is associated with the “FA 25” Error

“ON” or “OFF” When “ON”, the

“FA 25” alarm will automatically reset

when the condition clears

Choose “OFF”, “LO” or “HI” relay to

assert when the FA 25 Error is active

When AUTO25 is “OFF”, manually alarm Sets the Total Tap Change count alarm limit in THOUSANDS Selects which relay is associated with the Total Tap Change count

clears the alarm and opens the relay

n= a number from 0.00 to 999.99 with

two decimal place resolution

Choose “OFF”, “LO” or “HI” relay to

assert when the alarm limit is reached alarm

Presets the Total Tap Change counter

and clears the alarm

Sets the Total Tap Change

counter reference date

in THOUSANDS

Enables automatic reset of the “FA 27” Unstable Synchro Signal Error (page 50) Selects which relay is associated with the “FA 27” Error

n= a number from 0.00 to 999.99 with

two decimal place resolution

mm-dd-yyyy = Month <hyphen> Day

<hyphen>Year (4 digits)

“ON” or “OFF” When “ON”, the

“FA 27” alarm will automatically reset

when the condition clears

Choose “OFF”, “LO” or “HI” relay to

assert when the FA 27 Error is active

When AUTO27 is “OFF”, manually alarm

clears the alarm and opens the relay

Command Syntax: Function: Explanation:

OTGDLMT◊nn.nª

Sets the On-Tap guard band limit in DEGREES

OTRLY◊LOª

Selects which relay is associated with the On-Tap alarm

OTDVTNª Displays the tap with the greatest

On-Tap Deviation

OTDATE◊mm-dd-yyyyª

Sets the On-Tap reference date

OTCLRª Clears the On-Tap alarm Data is retained, the alarm is cleared OTRSTª Resets all On-Tap logs & alarm All On-Tap data is erased, alarm cleared UPDNLMT◊nnn.nnª

Sets the alarm limit for the number of changes “Up-To” and “Down-To” any tap

in THOUSANDS

UPDNRLY◊LOª

Selects which relay is associated with the “Up-To / Down-To” Change alarm

UPDNDATE◊mm-dd-yyyyª

Sets the Up To / Down To

Change counter reference date

UPDNCLRª Clears an active Up-To or

Down-To Change alarm

UPDNRSTª Resets all Change Up-To and

Down-To counters and alarm

PORT◊bbbb◊w◊p

◊s◊aª

Set comm. port settings: baud rate, word length, parity, stop bits, and address

SITEID◊Abcd-Xyz & 123ª

Identifies installation site on the “DUMP” header

PTNLMT◊nnnª

Sets the alarm limit for the number of DAYS without a “Pass Through Neutral”

PTNRLY◊LOª

Selects which relay is associated with the “Pass-Through-Neutral” alarm

PTNRSTª Resets the “Pass-Through-

Neutral” counter & alarm

1DTCLMT◊nnª

Sets the alarm limit for the number of consecutive tap changes in One Direction

1DTCRLY◊LOª

Selects which relay is associated with the “One Direction” alarm

1DTCCLRª Clears a “One Direction” alarm MENU◊1ª

Set the keyboard button menu type

n= a number of degrees from 0.0 to 99.9

with one tenth degree resolution

Choose “OFF”, “LO” or “HI” relay to

assert when the alarm limit is reached

Displays Tap Number and Deviation

mm-dd-

yyyy = Month <hyphen> Day

<hyphen>Year (4 digits)

n= a number from 0.00 to 999.99 with

two decimal place resolution

Choose “OFF”, “LO” or “HI” relay to

assert when the alarm limit is reached

mm-dd-yyyy = Month <hyphen> Day

<hyphen>Year (4 digits)

If a tap with an Up-To or Down-To Change

counter exceeding the programmed limit is

re-visited, the alarm will re-activate

All Up-To and Down-To counters are reset

to zero and an active alarm is turned off

2400, 4800, 9600, 14400, 19200,

28800, 38400, 57600, 76800 baud

w= 7 or 8 bit word

p= n, E, O

s= 1 or 2 stop bits

a= 0 to 255

40 ASCII Characters – Upper / lower case

letters, numbers, punctuation marks

n= a number from 0.0 to 365.0 with one

decimal place resolution

Choose “OFF”, “LO” or “HI” relay to

assert when the alarm limit is reached

n= an integer from 2 to 30, OFF

Choose “OFF”, “LO” or “HI” relay to

assert when the alarm limit is reached

“1” = Numeric “OP” menu or

“2” = Alpha-numeric menu

HELP◊(command) ª

Provides on-line help on the specific command entered or lists all available commands

An explanation of a command and the

proper entry syntax is given. If no

command is entered, all commands will

be listed with syntax but no explanations

To prevent accidental or unwanted changes to the program parameters, a jumper wire may be installed across terminals 3 & 4. With this jumper installed, the numeric menu will read “EP nn” instead of “OP nn”. All parameters can be viewed but no changes can be made.

Present Tap: 5 Total Tap Changes: 5729 Low Draghand: -7 35.4 Days Since LAST High Draghand: 8 17.6 Days Since LAST

ALARMS: Since activated - Days: Limit: Ref Date: On-Tap Deviation 0.65 3.0 08-30-2007 Instability -- -- Synchro Signal Lost -- - 1 Direction Change 0.86 04 Up Down Count -- 123456 08-30-2007 Total Tap Changes 0.66 1234567 08-30-2007 Low Tap -- -10 High Tap 0.86 12 Pass Through Neut 0.95 30.0

TAP STATISTICS: Tap Max. Dev. Change Change Num: Degrees: Up-To: Dn-To:

-16 + 0.0 0 0

-15 + 0.0 0 0

-14 + 0.0 0 0

-13 + 0.0 0 0

-12 - 0.4 0 1

-11 - 0.4 1 2

-10 - 0.3 2 3

-9 + 0.4 3 9

-8 + 0.5 9 85

-7 + 0.8 85 215

-6 + 0.9 215 608

-5 + 0.9 608 1935

-4 + 1.1 1935 5564

-3 + 1.2 5564 6258

-2 + 1.1 6258 7145

-1 + 1.3 7145 5199 0-1 + 0.0 5199 5199 0-2 - 1.3 5199 8064 0-3 + 0.0 8064 8064 1 + 1.4 8064 40792 2 + 2.2 40792 22186 3 + 1.9 22186 9420 4 + 1.4 9420 7384 5 + 1.2 7384 4008 6 + 0.9 4008 1523 7 + 0.7 1523 407 8 - 0.6 407 115 9 - 0.6 115 11 10 + 0.5 11 4 11 - 0.3 4 2 12 - 0.4 2 1 13 + 0.4 1 0 14 + 0.0 0 0 15 + 0.0 0 0 16 + 0.0 0 0

Visit

Figure 2.2 Serial Data Dump Example

2.3 Serial Port Programming - MODBUS:

This type of serial communication require the RS-232 (-S) or RS-485 (-M) hardware option. To communicate to the 1250-LTC with MODBUS protocol, connect a computer with the appropriate MODBUS communication software and serial port hardware to the 1250-LTC’s serial port cable. The computer must have the proper Comm port settings to communicate to the 1250-LTC (see Section 3.3, page 46). See Table 2.3 for a full listing of all MODBUS Registers, the definition and binary format for each.

In the following Table 2.3 the meanings of the columns is as follows:

Hex: The same register’s address in hexadecimal, this value is calculated by

subtracting 40001 from the register number. Thus register 40001 in decimal becomes 0000 in hex, and 40257 in decimal becomes 0100 in hex.

Function: Defines what each register contains or does when written. Some registers are read only and have no meaning when written. Others can be written or read. Others are “write only” special functions and cause actions to be performed when they are written.

Format: This column defines what a register contains bit-by-bit in binary. A row of 16 symbols shows what each of the 16 bits of the register contain MSB first and LSB last. A BCD formatted floating point register is shown as follows (two 16 bit binary words):

Bcdabcdbbcdcbcdd bcde000000vspppp

bcda, bcdb, bcdc, bcdd, bcde are each four-bit BCD digits, as it would be seen on a display. 000000 are 6 unused bits that report as 0 when read and must be 0 when written. v is an overflow bit that indicates that the number in the register is too big to display when it is a 1. 0 indicates a valid register value.

is the sign bit and is 1 when the value in the register is negative. 0

indicates a positive number.

pppp

is the position of the decimal point within the bcd digits.

Most registers are not as complex as a floating-point register.

An alternate floating-point format is supported and selected by writing a 1 to the 40256d (00ff h) register. This selects an IEEE floating-point format as follows (two 16 bit binary words):

seeeeeeeemmmmmmm mmmmmmmmmmmmmmmm

The format of the IEEE floating-point number is as follows:

s is the sign bit,

is the exponent bits, and

e m

are the mantissa bits.

The MODBUS protocol is a master/slave packet based protocol with the 1250-LTC operating as a RTU slave. The MODBUS function commands recognized by the 1250-LTC are “3” (read multiple registers) and “16” (write multiple registers). By supporting these two commands the 1250-LTC is in level 0 compliance. Using these two commands it is possible to configure the 1250-LTC as well as monitor it for current position. MODBUS RTU command and response packets are formatted as follows:

2.3.1 MODBUS Packet Format - Read

Reading from Holding Registers:

GAP = A gap in transmission of 3.5 character frames indicates to the slaves that a new packet is to follow. No transmission gaps within a packet may exceed 1.5 character frames.

Byte 1 = Device Address: Address 0 is a broadcast address that all units respond to regardless of programmed address. All other addresses can be programmed and used in this mode.

Byte 2 = Function Code: When reading holding registers, this byte is “03h”

Data Block = Begins with the number of the first register (two bytes) in a command packet,

or data from the first register (two bytes) in a response packet. Followed by the number of registers to be read (two bytes) in a command packet, or by data from subsequent registers.

Last 2 Bytes = Error Checking CRC – Lo Byte & Hi Byte

Table 2.3 Read Registers Command Format

GAP

3.5 Char

Min. 80h 03h 01h 03h 00h 04h xx xx

Device Address

Function Code

# of First Register Hi

# of First Register Lo

# of Registers to Read Hi

# of Registers to Read Lo

CRC

Table 2.4 Read Registers Response Format

GAP

3.5 Char

Min. 80h 03h 08h 01h 03h 00h 03h

Device Address

Function Code

Byte Count

Data from First Register Hi

Data from First Register Lo

Data from Second Register Hi

Data from Second Register Lo

…… …… Data from Last

Data from Last Register Lo

CRC

…… …… 00h 02h xx xx

2.3.2 MODBUS Packet Format - Write

Write to Holding Registers:

GAP = A gap in transmission of 3.5 character frames indicates to the slaves that a new packet is to follow. No transmission gaps within a packet may exceed 1.5 character frames.

Byte 1 = Device Address: Address 0 is a broadcast address that all units respond to regardless of programmed address. All other addresses can be programmed and used in this mode.

Byte 2 = Function Code: When writing to holding registers, this byte is “10h”

Data Block = Begins with the number of the first register to be written (two bytes), followed

by the number of registers to be written (two bytes), in either command or response packets. In a command packet the programming data for the first register will be the next two bytes followed by programming data for subsequent registers.

Last 2 Bytes = Error Checking CRC – Lo Byte & Hi Byte

Table 2.5 Write Registers Command Format

GAP

3.5 Char

Min. 80h 10h 10h 00h 00h 04h

Device Address

Function Code

# of First Register to be written to Hi

# of First Register to be written to Lo

# of Registers to Write Hi

# of Registers to Write Lo

Byte Count

Program Data for First Register Hi

Program Data for First Register Lo

Program Data for Second Register Hi

Program Data for Second Register Lo

08h 00h 01h 03h 60h

……

Program Data for Last Register Hi

Program Data for Last Register Lo

CRC

…… …… 00 01 xx xx

Table 2.6 Write Registers Response Format

GAP

3.5 Char

Min. 80h 10h 01h 00h 00h 04h xx xx

Device Address

Function Code

# of First Register to be written to Hi

# of First Register to be written to Lo

# of Registers to Write Hi

# of Registers to Write Lo

CRC

2.3.3 MODBUS Packet Format – Error Exception Response

When the master sends a command, the MSB bit in the Function Code is always clear. When a slave responds to the command, the slave leaves the MSB bit in the Function Code clear if the response is a normal response and sets MSB bit on if the response is an error exception response.

GAP = A gap in transmission of 3.5 character frames indicates to the slaves that a new packet is to follow.

Byte 1 = Device Address: Address 0 is a broadcast address that all units respond to regardless of programmed address. All other addresses can be programmed and used in this mode.

Byte 2 = Function Code: This byte will be the last command sent plus the MSB set on.

Exception Code = Illegal Command = 01 Illegal Register = 02

Last 2 Bytes = Error Checking CRC – Lo Byte & Hi Byte

Table 2.7 Error Exception Response Format

GAP

3.5 Char

Min. 80h 90h 02 xx xx

Device Address

Function Code

Exception Code

CRC

Table 2.8 RS-485 MODBUS Register Definitions

Class & Type Function: Binary Format: Address: Decimal [hex]

40001

[0000]

40002

[0001]

Class:

Configuration

Type:

Read\write

Class:

AlarmClearing,

AlarmStatus

Type:

Setup / run mode select

Synchro input signal status

Read\write,

Write 0 to clear 40257, 40258

[0100, 0101]

Class: State

Type: Read-only

Angle (cumulative)

[The value can exceed +\- 360.0 degrees]

40264

[0107]

40513

[0200]

Class: State

Type: Read-only

Class:

Configuration

Type: Write-only,

Tap, neutral

Draghand reset control

Write one to clear

40516

[0203]

Class: State

Type: Read-only

High tap draghand

000000000000000s

LSB (s) 0 – run mode 1 – setup mode

This bit must be 1 before any program parameter can be changed 000000000000000s

LSB (s) 0 – OK input signal is present 1 – ALARM input signal is lost

seeeeeeeemmmmmmm MSW mmmmmmmmmmmm LSW

IEEE 754-1985 single precision float

MSW = [0100] LSW = [0101] tttttttt0000nnnn

[“0000” are unused bits]

“t”= 8-bit tap number “n”= 4-bit neutral number (both in binary) 00000000000000HL

“H”= high draghand “L”= low draghand

0 ignored 1 = reset tttttttt0000nnnn

[“0000” are unused bits]

”= 8-bit tap number

“t “n

”= 4-bit neutral number

(both in binary)

Class & Type Function: Binary Format: Address: Decimal [hex]

40519

[0206]

Class: State

Type: Read-only

Low tap draghand

tttttttt0000nnnn

[“0000” are unused bits]

“t

”= 8-bit tap number “n”= 4-bit neutral number (both in binary)

40520

[0207]

Class: Configuration

Type: Read\write

Draghand counter start visit

000000000000000s

LSB (s) 0 – First 1 – Last

Selects whether time since first or last draghand visit to a tap is reported.

40769

[0300]

Class: State

Type: Read-only

Internal relay states

00000000000000HL

“H”= high relay “L”= low relay

If relay is on, bit = 1, else bit = 0

40777, 40778

[0308, 0309]

Class: State

Type: Read\write

Total tap change count

ssssssssssssssss MSW ssssssssssssssss LSW

MSW = [0308] LSW = [0309] [NOTE: Always write both the high (MSW) and low (LSW) words with consecutive writes; do not write any other register address between these two writes.]

40785

[0310]

Class: State

Type: Read-only

Tap, neutral with greatest on-tap deviation

tttttttt0000nnnn

[“0000” are unused bits]

”= 8-bit tap number

“t “n

”= 4-bit neutral number

(both in binary)

40786, 40787

[0311, 0312]

Class: State

Type: Read-only

Max measured on-tap deviation

seeeeeeeemmmmmmm MSW mmmmmmmmmmmm LSW

IEEE 754-1985 single precision float

MSW = [0311] LSW = [0312]

40801

[0320]

40802

[0321]

40803

[0322]

40804

[0323]

40805

[0324]

40806

[0325]

Class & Type Function: Binary Format:

Class: AlarmClearing, AlarmStatus

Type:

On-tap alarm state

000000000000000s

LSB (s

) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus Type: Read\write,

One-direction alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Write 0 to clear Class: AlarmClearing, AlarmStatus

Type:

Instability alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus

Type

Loss-of-signal alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus

Type:

Change up-to \ down-to alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus

Pass-throughneutral alarm state

000000000000000s LSB (s) 0 – OK 1 – ALARM

Type: Read\write, Write 0 to clear

40807

[0326]

40808

[0327]

40809

[0328]

40833

[0340] 40834

[0341] 40835

[0342]

40836

[0343]

40837

[0344]

40838

[0345]

Class & Type Function: Binary Format:

Class: AlarmClearing, AlarmStatus

Type:

Total tap change alarm state

000000000000000s

LSB (s

) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus

Type:

Low tap alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmClearing, AlarmStatus

Type

High tap alarm state

000000000000000s

LSB (s) 0 – OK 1 – ALARM

Read\write, Write 0 to clear Class: AlarmStatus

Type: Read-only Class: AlarmStatus

Type: Read-only

Days since asserting On-tap alarm Days since asserting Onedirection alarm Days since asserting Instability

dddddddddddddddd

“d” = 10ths of a day dddddddddddddddd

“d” = 10ths of a day

dddddddddddddddd

“d” = 10ths of a day

Alarm

Class: AlarmStatus

Type: Read-only

Days since asserting Loss-of –Signal

dddddddddddddddd

“d” = 10ths of a day

Alarm

Class: AlarmStatus

Type: Read-only

Days since asserting Upto\down-to

dddddddddddddddd

“d” = 10ths of a day

alarm

Class: AlarmStatus

Type: Read-only

Days since last Pass–throughneutral

dddddddddddddddd

“d” = 10ths of a day

40839

[0346]

40840

[0347] 40841

[0348] 40842

[0349] 40843

[034A] 40865

[0360]

40869

[0364]

40870

[0365]

41025

[0400]

Class & Type Function: Binary Format:

Class: AlarmStatus

Type: Read-only

Days since asserting Total tap changes

dddddddddddddddd

“d” = 10ths of a day

alarm

Class: AlarmStatus

Type: Read-only Class: AlarmStatus

Type: Read-only Class: AlarmClearing, StatisticsResetting

Type: Write-only,

Days since asserting Low tap alarm Days since asserting High tap alarm Days since Low draghand hit new extremum Days since High draghand hit new extremum

dddddddddddddddd

“d” = 10ths of a day dddddddddddddddd

“d” = 10ths of a day

On-tap reset 000000000000000s

LSB (s) 0 = reset 1 = ignored

Write 0 to clear Class: AlarmClearing, StatisticsResetting

Type:

Up-to/down-to reset

000000000000000s

LSB (s) 0 = reset 1 = ignored

Write-only, Write 0 to clear Class: AlarmClearing, StatisticsResetting

Type:

Pass-throughneutral reset

000000000000000s

LSB (s

) 0 = reset 1 = ignored

Write-only, Write 0 to clear Class: state

Type:

Analog output 0000aaaaaaaaaaaa

12-bit number (in binary)

Read-only

44097

[1000]

44353

[1100]

44354, 44355

[1101, 1102 ]

44356

[1103]

44357

[1104]

44358

[1105]

44867

[1302]

44868

[1303]

Class & Type Function: Binary Format:

Class: Configuration

Type:

Operating mode

00000000000mmmmm

LSBs (mmmmm

)

(see list of modes on page 34)

Read\write Class: Configuration

Number of taps 000000000nnnnnnn

7-bit number (in binary)

Type: Read\write Class: Configuration Type: Read\write

Degrees per segment

seeeeeeeemmmmmmm MSW mmmmmmmmmmmm LSW

IEEE 754-1985 single precision float

MSW = [1101] LSW = [1102]

Class: Configuration

Type: Read\write Class: Configuration

Number of neutrals

Neutral start segment

Display “r”&“L”

Preset tap

000000000000nnnn

LSBs (nnnn) Up to 8 neutrals, in binary. If field value > 8, clamps to 8 ssssssssssssssss

16 bits, first neutral tap

000000000000000d

LSB(d

) 0 = disabled 1 = enabled ssssssssssssssss

16 bits, preset tap no.

Type: Read\write Class: Configuration

Type: Write-only

Load/clear preset control

00000000000000cc

LSBs (cc) 00 – no operation 01 – clear offset 10 – load preset

45121

[1400]

45122

[1401]

45155

[1422]

45156

[1423]

45633

[1600]

45634

[1601]

Class & Type Function: Binary Format:

Class: Configuration

Type: Read\write Class: Configuration

Type: Read\write Class: Configuration, AlarmClearing

Type:

Display blank 000000000000000b

LSB(b) 0 = disabled 1 = enabled [display will blank]

Menu mode 000000000000000m

LSB (m) 0= numeric 1=alphanumeric

Auto reset 27 0000000 e

LSB (e

) 0 = disabled 1 = enabled

Read\write Class: Configuration, AlarmClearing

Type:

Auto reset 25 0000000 e

LSB (e) 0 = disabled 1 = enabled

Read\write Class: Configuration

Type: Read\write

RS-232 mode 0000000000000rrr

LSBs (rrr) 000 = Serial disabled 001 = datalogger mode 010 = polled mode 011 = sampled mode 100 = command 101 = reserved N/A 110 = RS485 Modbus 111 = remote display driver

Class: Configuration

Type: Read\write

Baud 000000000000bbbb

LSBs (bbbb) 0000 = 300 0001 = 1200 0010 = 2400 0011 = 4800 0100 = 9600 0101 = 14400 0110 = 19200 0111 = 28800 1000 = 38400 1001 = 57600 1010 = 76800

45635

[1602]

45636

[1603]

45637

[1604]

45638

[1605]

45889, 45890

[1700, 1701]

45891

[1702]

45892

[1703]

45893

[1704]

Class & Type Function: Binary Format:

Class: Configuration

Type: Read\write Class: Configuration

Type: Read\write

Word length 000000000000000w

LSB (w

) 0 = 7 bits 1 = 8 bits

Parity 00000000000000pp

LSBs (pp) 00 = none 01 = even 10 = odd

Class: Configuration

Type: Read\write Class: Configuration

Type:

Stop bits 000000000000000s

LSB (s) 0 = 1 bits 1 = 2 bits

Address 00000000aaaaaaaa

LSBs (aaaaaaaa) 8-bit serial multidrop address

Read\write Class: Configuration

Type: Read\write

Total tap change counter limit

seeeeeeeemmmmmmm MSW mmmmmmmmmmmm LSW

IEEE 754-1985 single precision float

MSW = [1700] LSW = [1701] (in thousands of counts)

Class: Configuration

Type: Read\write

Total tap change count alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Type:

Reference year for Total tap change counter

0000yyyyyyyyyyyy

“y” = Year (in binary)

Read\write Class: Configuration

Type: Read\write

Reference date for Total tap change counter

0000mmmm 000ddddd

“m” = Month (January = 1) “d” = Day (1-31) (in binary)

46145

[1800]

46146

[1801]

46147

[1802]

46148

[1803]

46401, 46402

[1900, 1901]

46403

[1902]

46404

[1903]

46405

[1904]

Class & Type Function: Binary Format:

Class: Configuration

Type:

On-tap guard band limit

dddddddddddddddd

“d” = tenths of a degree (in binary)

Read\write Class: Configuration

Type: Read\write

On-tap alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Type:

Reference year for On-tap counter

0000yyyyyyyyyyyy

“y” = Year (in binary)

Read\write Class: Configuration

Type: Read\write Class: Configuration

Type: Read\write

Reference date for On-tap counter

Change up-to / down-to counter limit

0000mmmm 000ddddd

“m” = Month “d” = Day (in binary) seeeeeeeemmmmmmm MSW mmmmmmmmmmmm LSW

IEEE 754-1985 single precision float

MSW = [1900] LSW = [1901] (in thousands of counts)

Class: Configuration

Type: Read\write

Change up-to / down-to counter alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Type:

Reference year for up-to / down-to counter

0000yyyyyyyyyyyy

“y” = Year (in binary)

Read\write Class: Configuration

Type: Read\write

Reference date for up-to / down-to counter

0000mmmm 000ddddd

“m” = Month “d” = Day (in binary)

46657

[1A00]

46658

[1A01]

46913

[1B00]

46914

[1B01]

47169

[1C00]

47170

[1C01]

47425

[1D00]

47426

[1D01]

Class & Type Function: Binary Format:

Class: Configuration

Type:

Pass-throughneutral limit

dddddddddddddddd

“d” = tenths of a day (in binary)

Read\write Class: Configuration

Type: Read\write

Pass-throughneutral counter alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Type:

One-direction counter limit

0000000000ssssss

LSBs(ssssss) 6-bits, number of taps

Read\write Class: Configuration

Type: Read\write

One-direction counter alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Low tap relay limit

ssssssssssssssss

16-bit signed word, low tap limit

Type: Read\write Class: Configuration

Type: Read\write

Low tap alarm relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

High tap relay limit

ssssssssssssssss

16-bit signed word, high tap limit

Type: Read\write Class: Configuration

Type: Read\write

High tap alarm relay

00000000000000 rr

LSBs (rr

) 00 – OFF 01 – LO Relay 10 – HI Relay

47938

[1F01]

47939

[1F02]

47940

[1F03]

48193

[2000]

48194

[2001]

48705

[2200]

Class & Type Function: Binary Format:

Class: Configuration

Type: Read\write

Tap change acknowledge relay

00000000000000 rr

LSBs (rr

) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Acknowledge relay delay time

000000000sssssss

“s” = Delay in tenths of a second

Type: Read\write Class: configuration

Acknowledge relay duration time

000000000sssssss

“s” = Duration in tenths of a second

Type: Read\write Class: Configuration

Type: Read\write

“FA 25” error relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: Configuration

Type: Read\write

“FA 27” error relay

00000000000000 rr

LSBs (rr) 00 – OFF 01 – LO Relay 10 – HI Relay

Class: State

Type: Read\write

Tap index select

00000000 uuuuuuuu

Unsigned byte Zero-based index of tap ( value <= 39 decimal)

** NOTE: ALWAYS initially write the tap index select register before reading any of the tap attribute registers 0x3001 through 0x3007; that single write will suffice until it’s desired to select a different tap index, at which time another write of the new tap index to this register is required. Also write this register if a restart may have occurred since the last write; i.e. the value of tap index select is not retained over a reset.

48706

[2201]

48707

[2202]

48708

[2203]

48709, 48710

[2204, 2205]

48711, 48712

[2206, 2207]

Class & Type Function: Binary Format:

Class: State

Type: Read-only

Tap number corresponding to Tap index

ssssssssssssssss

Signed 16-bit word

select

Class: State

Type: Read-only

Neutral number corrresponding to Tap index

uuuuuuuuuuuuuuu

Unsigned 16-bit word

select

Class: State

Type: Read-only

Class: State

Type: Read-only

Max On-Tap deviation corresponding to Tap index select Upper and lower words of Up-to count corresponding to Tap index select

ssssssssssssssss

Signed 16-bit word denoting tenths of a degree

uuuuuuuuuuuuuuuu MSW uuuuuuuuuuuuuuuu LSW

Unsigned 32-bit longword denoting upto count.

MSW = [3004] (upper) LSW = [3005] (lower)

** NOTE: To obtain a consistent 32-bit value, ALWAYS read 0x3004 BEFORE 0x3005; DO NOT read or write any other register address between these reads.

Class: state

Type: Read-only

Upper and lower words of Down-to count corresponding to Tap index select

uuuuuuuuuuuuuuuu MSW uuuuuuuuuuuuuuuu LSW

Unsigned 32-bit longword denoting down-to count

MSW = [3006] (upper) LSW = [3007] (lower)

** NOTE: To obtain a consistent 32-bit value, ALWAYS read 0x3006 BEFORE 0x3007; DO NOT read or write any other register address between these reads.

2.4 Operating Modes:

The model 1250-LTC has six operating modes. Each mode causes the 1250-LTC to function differently. Determine which of the following operating modes is best suited to your application. The proper mode will depend upon the desired numbering of the taps and where the neutral taps are located:

16 = Base 1 Uni-polar Segmented Linear Analog (Neutrals can be at any tap number) 17 = Base 1 Uni-polar Segmented Stepped Analog (Neutrals can be at any tap number) 18 = Base 0 Uni-polar Segmented Linear Analog (Neutrals always at “0”) 19 = Base 0 Uni-polar Segmented Stepped Analog (Neutrals always at “0”) 20 = Bi-polar Segmented Linear Analog (Neutrals always at “0”) 21 = Bi-polar Segmented Stepped Analog (Neutrals always at “0”)

Modes 16 & 17: Base 1 Uni-polar Segmented

These modes are used for LTC monitoring when the lowest tap number is 1. There may be multiple neutral taps. They can be located anywhere between the lowest and highest taps as long as they are grouped together in one section. Mode 16 has a linear analog output that continuously varies with LTC shaft position. Mode 17 has a stepped analog output that jumps with each tap change. To select this operating mode use the OP 2, Func, MODE command to change the value to “16” or “17”.

Figure 2.3 Base 1 Uni-polar Mode Analog Output

Programming Example:

A typical transformer Load Tap Changer application with taps numbered 1 to 32,

2 neutral taps (17-1 and 17-2), with 9.5

per tap, presently set on tap “18” would be

programmed as follows:

OP 2 Operating mode = 17 OP 20 Number of taps = 33 OP 21 Degrees per tap = 9.5000 OP 22 Number of neutrals = 2 OP 23 Lowest neutral tap = 17 OP 27 Present tap = 18 OP 28 Load present tap

Modes 18 & 19: Base 0 Uni-polar Segmented These modes are used for LTC monitoring when the lowest tap number is 0. There may be multiple neutral taps, but they can only be located at tap 0. Mode 18 has a linear analog output that continuously varies with LTC shaft position. Mode 19 has a stepped analog output that jumps with each tap change. To select this operating mode use the OP 2, Func, MODE command to change the value to “18” or

“19”.

Figure 2.4 Base 0 Uni-polar Mode Analog Output

Programming Example:

A typical transformer Load Tap Changer application with taps numbered 0 to 16, 2 neutral taps, with 10.5o per tap, presently set on tap “9” would be programmed as follows:

OP 2 Operating mode = 19 OP 20 Number of taps = 18 OP 21 Degrees per tap = 10.500 OP 22 Number of neutrals = 2 OP 27 Present tap = 9 OP 28 Load present tap

Modes 20 & 21: Bi-polar Segmented These modes are used for LTC monitoring when the neutral tap(s) are in the center of the dial and there is an equal number of raised and lowered taps. There may be multiple neutral taps, but they can only be located at tap 0. Mode 20 has a linear analog output that continuously varies with LTC shaft position. Mode 21 has a stepped analog output that jumps with each tap change. To select this operating mode use the

OP 2, Func, MODE command to change the value to “20” or “21”.

Figure 2.5 Bi-polar Mode Analog Output

Programming Example:

A typical transformer Load Tap Changer application with 16 raised and 16 lowered

taps, 3 neutral taps, with 10

per tap, presently set on tap “2L” would be programmed as

follows:

OP 2 Operating mode = 21 OP 20 Number of taps = 35 OP 21 Degrees per tap = 10.000 OP 22 Number of neutrals = 3 OP 27 Present tap = -2 OP 28 Load present tap

2.5 Programming Notes:

If the Degrees Per Tap value is not known, the 1250-LTC can be used to determine this value. Follow these steps to determine the Degrees Per Tap value:

1) Enter the Programming Menu and select OP 19 (Degrees Mode) and press the ENTER

key.

3) The 1250-LTC should read a number from 0.0 to 359.9 with 1 decimal place.

4) Move the LTC to as many taps as possible. Record each tap number and the

corresponding degree reading displayed on the 1250-LTC in the table below.

5) Subtract one degree reading from the next, for each tap, and write it in the “Difference”

column in the table.

6) The differences should all be approximately the same. Take an average of the numbers in

the Difference column. The result is the Degrees Per Tap number that the 1250-LTC needs for the OP 21, D SEG, or DEGSEG command.

7) Press the ENTER key to return to the Programming Menu.

Tap Number Degrees Difference Tap Number Degrees Difference

There is no programming required for the Analog Output. It automatically spans the full range of taps, lowest tap to low output, highest tap to high output. Programming for the High/Low Relays option is covered in Section 3.2, page 40. Programming for the Serial ASCII Communication option is covered in Section 2.2, page 13. Programming for the Serial MODBUS Communication option is covered in Section 2.3, page

18.

3.0 OPTIONS

The standard Model 1250-LTC is configured with three options – Analog Output, Hi/Lo Relays, and a Serial Port (RS-232 or RS-485). One more option is available – Input Isolation. This section describes general use of each option, including wiring and programming for each option.

3.1 Analog Output Option “-0”, “-1”, “-2”, “-4”

The analog output on the 1250-LTC may be used to feed position information to an LTC Controller, a remote monitoring system such as SCADA, RTU or a remote indicator such as the INCON model 1511-Z. In the all modes, the analog output automatically spans between the highest and lowest taps.

Wiring:

The 4-20mA analog output option must be wired with an external power supply of

15.0 to 24.0 volts DC in series with the analog output current loop. (See Figure 1.3, page 7) The INCON Model 1945 is available for this purpose. All other analog output options are self-powered. Refer to Table 3.1 below for analog output load limits.

Table 3.1 Analog Output Load Limits

Analog Output: Load Minimum Load Maximum

0 to 1 mA Zero Ohms 10K Ohms +/- 1 mA Zero Ohms 10K Ohms 0 to 2 mA Zero Ohms 5K Ohms 4-20 mA Zero Ohms 500 Ohms

Note:

If the presence of high voltage AC “ripple” is found on the analog output terminals, it is generally not a problem with the 1250-LTC itself. Check the isolation of all field wiring with respect to earth ground. All wiring should be completely isolated from ground. See Section 3.5, page 48 Input Isolation Option. Contact INCON Technical Service for assistance if the problem persists.

3.2 High / Low Relay Limits Option “-R”

In the 1250-LTC, the High / Low Relays serve as alarm annunciators for the many programmable limits associated with expanded LTC monitoring. The (two) relays are normally open, dry contacts. Each relay may have one or more of the alarm limits assigned to it. They may be used as feedback in a control system or as an alarm when the parameter has reached its desired limits.

When the Tap Change Acknowledgement is not used, it is recommended that the desired alarms be divided into two groups: Warning (LO) and Danger (HI). Less important parameters should cause one relay (Warning) to turn on and more important parameters should cause the other relay (Danger) to turn on. This way, the level of seriousness of an alarm could be communicated, when remotely monitored. When the Tap Change Acknowledgement is assigned to one relay (HI or LO), all other desired alarms must be assigned to the other relay (LO or HI).

When the LO relay is asserted, the LED above the DOWN button, below the digital display, will flash. When the HI relay is asserted, the LED above the UP button, below the digital display, will flash. Note that the LED’s will flash even if the “-R” Relay Option is

not installed. This will alert an operator that an alarm limit has been reached, even on an instrument without Relays. In addition to flashing the HI & LO Relay LED’s, an alarm

code(s) will be momentarily displayed, every 10 seconds, to explain which specific alarm(s) is causing the alarm condition.

Figure 3.1 Relay Field Wiring Diagram

Since the instrument has only two relays, and eight possible uses for those two relays, there may be times when a relay is being asserted by more than one alarm. The relay actions fall into three categories: Momentary; Transient; and Persistent. A Momentary action, as the name implies, closes the relay for only a moment, then opens the relay. The Tap Change Acknowledge is the only Momentary use of a relay. A Transient action is one that keeps the relay closed as long as a condition remains valid. As soon as the condition goes away, the relay will open. The High Tap & Low Tap Alarms and the FA 25 and FA 27 Error Alarms are the only Transient uses of a relay. A Persistent action is one in which the relay remains closed until it is manually reset by the operator. The Total Tap Change Count

Alarm, On-Tap Alarm, Up-To & Down-To Change Alarms, Pass Through Neutral Alarm, One Direction Change Alarm are Persistent uses of a relay.

Relay Assertion Priority: Any Persistent relay action takes priority over any

Transient or Momentary action. The Tap Change Acknowledgement Relay can not be assigned to the same relay as another alarm.

3.2.1 Tap Change Acknowledgement Relay

The 1250-LTC can momentarily close a relay contact following every detected tap position change. The user can program a delay time of 0.1 to 9.9 seconds, which causes the relay to wait before asserting. The user can also program a duration time of 0.1 to 9.9 seconds, which causes the relay to hold its assertion before turning off.

Use the OP 3, tCrLY, ACKRLY command to choose which relay output (OFF, LO or HI) will be asserted following every tap position change. When this value is set to “OFF” this function is disabled. Do not assign another alarm to the same relay assigned to for Tap Change Acknowledgement. Use the OP 4, tCrdL, ACKDLY command to set the delay time. Use the OP 5, tCrLt, ACKHOLD command to set the duration time.

3.2.2 High Tap Relay and Low Tap Relay

The 1250-LTC can close a relay contact when the LTC moves beyond programmable upper and lower position limits. When the LTC tap position value reaches the Low Relay limit, the assigned Low Tap Relay turns on, the appropriate Relay LED will light up, and the alarm code “LOtAP” will be displayed momentarily. When the position value rises above the Low Relay limit, the Low Tap Relay & LED will turn off and the alarm code will not be displayed. When the tap position value reaches the High Relay limit the assigned High Tap Relay turns on, the appropriate Relay LED will light up, and the alarm code “HItAP” will be displayed momentarily. When the value falls below the High Relay limit, the High Tap Relay & LED turn off and the alarm code will not be displayed. The user can separately program which relays will assert for the upper and lower position limits.

Use the OP 15, rL Lt, LTLMT command to set the Low Tap Relay Limit and the

OP 17, rL Ht, HTLMT command to set the High Tap Relay Limit. Use the OP 16, LtrLY, LTRLY command to select which relay (OFF, LO or HI) asserts when the Low Tap Relay

Limit is reached. Use the OP 18, HtrLY, HTRLY command to select which relay (OFF, LO or HI) asserts when the High Tap Relay Limit is reached. These are Transient relay actions. When these values are set to “OFF” this functions are disabled.

3.2.3 Total Tap Change Count Relay

The 1250-LTC can count the number of tap position changes and turn on a relay and LED when a programmed limit (10 to 999,990 counts) is reached. The alarm code “ttCLt” will also be displayed momentarily. The counter can be pre-set to any number. A date can be entered for reference purposes when the count is preset. (This date is stored in memory for reference only, it will not increment as time passes. It can be read through the Front Panel or the serial port.) The user can program which relay will assert when the Total Tap Change Count limit is reached. Please note that the counter limit and pre-set values are set in THOUSANDS of tap changes. For example, if an alarm is required at 125,000 operations, set the alarm limit to “0125.0”. If it is known that the LTC already has 2,300 operations, preset the counter to “0002.3”.

Use the OP 55, ttCLt, TTCLMT command to set the Total Tap Change Count Limit. Use the OP 56, ttrLY, TTCRLY command to select which relay (OFF, LO or HI) asserts when the Total Tap Change Count Limit is reached. When this value is set to “OFF” this function is disabled. Use the OP 57, ttPrE, TTCPRE command to pre-set the Total Tap Change Counter value. If the alarm relay is asserted, it will be cleared when the counter is preset to a value lower than the alarm limit. Use the OP 58, ttPdt, TTCDATE command to enter a reference date. To do this using the programming menu: Select OP 58, ttPdt and press the ENTER key. First, set the Day of the month value and press the ENTER key. Next, set the Month value and press the ENTER key. Finally, set the Year value and press the ENTER key. Use the OP 59, ttCdS, DUMP command to display the present counter value and the reference date. The counter value will be displayed for 2 seconds, and then the date will scroll across the display. This will repeat until the ENTER key is pressed, which will exit the command.

3.2.4 On-Tap Alarm Relay

The 1250-LTC has the accuracy and resolution to monitor minute differences in LTC tap position. Ideally, the LTC should always stop in the exact center of each tap position. A properly functioning LTC should consistently stop within a tolerable band of degrees, with every tap change. As the mechanism wears or if something breaks, the LTC may begin to stop in positions further from the center of the tap position, on one or more taps.

The 1250-LTC can be programmed to give an alarm when it detects that the LTC has stopped in a position that is outside the tolerable band of degrees. The width of this band of tolerable error is programmable in degrees, with 0.1 degree resolution.

A three second time window is given for the LTC to be outside of the acceptable Guard Band area. After three seconds, if the LTC is found in the “Error Zone”, the On-Tap Alarm Relay will assert.

Figure 3.2 On-Tap Example

Figure 3.1 is an example of an LTC with 10.0 degrees per tap position. This LTC should stop at the “zero degrees” center point on every tap, plus or minus a programmable tolerance (“Guard Band”) of 1.5 degrees (green area). If the LTC ever stops more than 1.5 degrees from the center (red area) of any tap, the On-Tap Alarm Relay will be asserted and an LED will flash. The alarm code “OtGLt” will be displayed momentarily. Use the OP 62, OtGLt, OTGDLMT command to set the On-Tap Guard Band tolerance in degrees, +/- from zero. Use the OP 63, OtrLY, OTRLY command to select which relay (OFF, LO or HI) asserts when the On-Tap Guard Band is reached. When this value is set to “OFF” this function is disabled. Use the OP 63, OtdtE, OTDATE command to enter a reference date.

Use the OP 65, OtdIS, DUMP command to display each tap and the highest measured deviation for that tap. Use the UP and DOWN keys to scroll through the list of taps. Press the ENTER key to select a tap and display its highest measured deviation in

degrees with 1/10

degree resolution and (-) sign (example: 1.3 or -0.9). Press the ENTER key to return to the list of taps. Press the MENU key to escape back to the programming menu.

Use the OP 66, Otdtd, command (menu only) to display all taps that exceed the deviation limit. Press the ENTER key to display the measured deviation for each. Use the UP and DOWN keys to scroll through the list of taps. Press the ENTER key to select a tap and display its highest measured deviation. Press the Enter key to return to the programming menu. Use the OP 67, OtrSt, OTRST command to reset all On-Tap logs. This command will also clear an active On-Tap alarm.

3.2.5 Up-To / Down-To Count Alarm Relay

Contacts in the LTC wear proportionately to the number of changes they endure. In most LTC’s the contact surface used in changing Up-To a tap is different than the surface used in changing Down-To the same tap. As the 1250-LTC is monitoring the movement of the LTC, it will keep a log of how many times the LTC changes Up-To and Down-To each tap. A programmable alarm limit (10 to 999,990 counts) can be set, which will assert the assigned Alarm Relay output and light up the associated LED, if the number of logged changes Up-To or Down-To any tap reaches the limit. The alarm code “udCLt” will be displayed momentarily. Please note that the counter limit value is set in THOUSANDS of tap changes. A date can be entered for reference purposes. (This date is stored in memory for reference only, it will not increment as time passes. It can be read through the Front Panel or the serial port.)

Use the OP 70, udCLt, UPDNLMT command to set the Up-To / Down-To Change Alarm Limit. Use the OP71, udrLY, UPDNRLY command to select which relay (OFF, LO or HI) asserts when the Up-To / Down-To Change Alarm Limit is reached. When this value is set to “OFF” this function is disabled.

Use the OP 73, uddIS, DUMP command to display each tap, the Change Up-To Count, and the Change Down-To Count for that tap. Use the UP and DOWN keys to scroll through the list of taps. Press the ENTER key to select a tap and display its Change Up-To Count. Press the ENTER key to display its Change Down-To Count. Press the ENTER key to return to the list of taps. Press the MENU key to escape back to the programming menu.

The alarm relay will remain asserted until cleared or the counters are reset. Use the OP 74, udCLr, UPDNCLR command to clear an active alarm without resetting the counters. Use the OP 75, udrSt, UPDNRST command to clear the alarm and reset all Change Up-To and Change Down-To counters. The display will read “rESEt”. When using the keyboard command, press the UP and DOWN keys at the same time to confirm that you want to reset these counters to zero. Press the MENU key to escape back to the programming menu without clearing the counters.

3.2.6 Pass-Through-Neutral Alarm Relay

It is important that an LTC pass through the neutral tap(s) on a regular basis. As the 1250-LTC monitors LTC position, it knows when the LTC passes through the neutral tap(s).

The 1250-LTC is intelligent enough to know the difference between stopping at neutral and reversing direction, and stopping at neutral and continuing on to the tap on the opposite side of neutral. A timer is started each time a complete “Pass-Through-Neutral” occurs. It counts the number of days since that event. When the LTC passes through neutral again, the timer is reset and counting starts over. A programmable limit is set, which will cause an assigned Alarm Relay output to assert and associated LED to light up, if the number of days since a “Pass-Through-Neutral” reaches this limit. The alarm code “PtnLt” will be displayed momentarily.

Use the OP 85, PtnLt, PTNLMT command to set the “Pass-Through-Neutral” Alarm Limit (0.1 to 365.0 days with 0.1 day resolution). Use the OP86, PtrLY, PTNRLY command to select which relay (OFF, LO or HI) asserts when the “Pass-Through-Neutral” Alarm Limit is reached. When this value is set to “OFF” this function is disabled. Use the OP 87, PtdIS, DUMP command to display the number of days since the last “Pass-ThroughNeutral” occurred. The relay will remain asserted until the alarm is cleared. Use the OP 88, PtnCL, PTNCLR command to reset the “Pass-Through-Neutral” counter. This command will also clear an active “Pass-Through-Neutral” alarm.

3.2.7 One-Direction Change Alarm Relay

Typically, an LTC will move a few taps up or down, then reverse direction and move a few taps, and reverse direction again. In most cases, it is unusual that the LTC will move very many taps consecutively in one direction. If this occurs, it may indicate some sort of failure in the position control system. The consequences of an out-of-control LTC could be serious – especially in the case of parallel transformers.

As the 1250-LTC monitors LTC position, it can be programmed to assert an alarm relay if it sees the LTC move too many taps consecutively in one direction, up or down. A programmable alarm limit (2 to 50) can be set, which will cause an assigned Alarm Relay output to assert and associated LED to light up, if the number of consecutive tap changes in one direction reaches this limit. The alarm code “1dCLt” will be displayed momentarily.

Use the OP 90, 1dCLt, 1DTCLMT command to set the “One Direction Change” Alarm Limit. Use the OP 91, 1drLY, 1DTCRLY command to select which relay (OFF, LO or HI) asserts the FIRST TIME the “One Direction Change” Alarm Limit is reached. When this value is set to “OFF” this function is disabled. Use the OP 93, 1ddIS, 1DTCDIS command to display the number of days since the “One Direction Change” alarm was asserted. The relay will remain asserted until the alarm is cleared. To clear the alarm, use the

OP 93, 1dACL, 1DACLR command.

3.2.8 FA 25 and FA 27 Alarm Relays

The 1250-LTC continuously performs sophisticated analysis of the input signal. If it detects a loss of signal, it will display an error code “FA 25”. If it detects that the input signal has been unstable (caused by noise or continuous LTC movement) for more than 5 seconds, it will display an error code “FA 27”. These alarms can be programmed to “automatically reset” when the condition is no longer valid. It can be programmed to assert an alarm relay when each of these errors occurs. These are Transient relay actions.

Use the OP 53, Aut25, AUTO25 command to enable or disable the automatic reset for the FA 25 error alarm. Use the OP 54, 25rLY, FA25RLY command to select which relay (OFF, LO or HI) asserts while the FA 25 error is being displayed. Use the OP 60, Aut27, AUTO27 command to enable or disable the automatic reset for the FA 27 error alarm. Use the OP 61, 27rLY, FA27RLY command to select which relay (OFF, LO or HI) asserts while the FA 27 error is being displayed.

3.3 Serial RS-232 “-S”

The Serial RS-232 option on the Model 1250-LTC can be used to program the instrument or to retrieve position data from the instrument. It is a full-duplex, DCE configuration.

The communication port settings: baud rate, word length, parity, stop bits, and address are programmable using the OP 80, POrt, PORT command. (See Table 2.1 and 2.2 for command protocol and choices.)

NOTE: When the port is programmed for 2 Stop Bits, the Parity must be “NONE”.

There are seven operating modes for the serial RS-232 port:

Serial Disabled the OP 51, RS232, SERIAL command to choose mode “0”. If you are programming the instrument through the serial port, using the serial command mode, this “disabled” mode will not take effect until the command “EXIT” is entered. The only way to de-select this “disabled” mode is to use the menu command OP 51, RS232, and select another mode.

Data Logger Mode value on the display (including sign) once a second. To select this mode use the OP 51, RS232, SERIAL command to choose mode “1”. If you are programming the instrument through the serial port, using the serial command mode, this mode will not take effect until the command “RESTART” is entered.

Polled Mode When this mode is selected, the 1250-LTC can be interrogated at any time via the RS-232 port for the current position. This is done by first instructing the 1250-LTC to latch the current position by transmitting an asterisk (*) to the unit. The position is then extracted, one character at a time, by transmitting the digits 0 through 6. Zero causes the sign character to be transmitted, 1 through 6 causes each position digit to be sent. The decimal point, wherever it may be positioned, is considered to be a digit. To select this mode use the menu command OP 51, RS232, SERIAL command to choose mode “2”.

Sampled Mode time via the RS-232 port for current position by transmitting a question mark (?) to the 1250-LTC. When the 1250-LTC receives a question mark, it responds by latching the current position and transmitting the value on the display in ASCII form. To select this mode use the menu command OP 51, RS232, SERIAL command to chose mode “3”.

Serial Command Mode This mode enables programming the instrument through the

serial port. To select this mode use the menu command OP 51, RS232 to choose mode “4”. When this mode is selected, no other serial communication can occur. In addition, if another Serial mode is chosen it will not be activated until the “EXIT” command is given through the serial port command line.

This mode stops all serial communication. To select this mode use

This mode causes the 1250-LTC to transmit the present position

When this mode is selected, the 1250-LTC can be interrogated at any

MODBUS Mode When this mode is selected, the 1250-LTC will respond to MODBUS commands via the serial port. This option requires the RS-485 (-M) or RS-232 (-S) hardware option be installed. To select this mode use the menu command OP 51, RS232 command to choose mode “6”. (See Section 2.3, page 18 for programming instructions.)

Remote Display Driver Mode This mode must be used when the 1250-LTC is connected to an INCON model RD4 Remote Display. It causes the 1250-LTC’s RS-232 output to transmit the proper protocol and timing for the RD4 to mimic what is on the 1250-LTC’s display. To select this mode use the menu command OP 51, RS232 command to choose mode “7”.

3.4 Serial RS-485 Multi-Drop Option “-M”

The Serial RS-485 option on the Model 1250-LTC can be used to program the instrument and to retrieve position data from the instrument, very much like the RS-232 option. It is a half-duplex configuration.

MODBUS is the most likely protocol to use for a 1250-LTC equipped with RS-485, but the 1250-LTC with RS-485 will operate in all of the same serial modes listed above in Section 3.3. Certain restrictions apply due to the nature of the half-duplex configuration: The device communicating to the 1250-LTC must be able to turn off its transmitter very quickly so that the 1250-LTC can respond over the same transmission lines. The Remote Display Driver mode is not useful, since the model RD-4 will only accept an RS-232 signal.

Table 3.8 Wiring: Digital Connector Pin-Out

DB-25 Pin#

1 1 Chassis Gnd. Chassis Gnd. 14 2 2 3 Transmit (O) Data A(I/O) + 15 4 3 5 Receive (I) Data B(I/O) – 16 6 4 7 RTS (O) Not Used 17 8 5 9 CTS (I) Not Used 18 10 6 11 19 12 7 13 Signal Gnd. Signal Gnd. 20 14 8 15 21 16 9 17 22 18 10 19 23 20

1250-LTC Pin#

RS-232 Function

RS-485 Function

3.5 Input Isolation Option “-I”

The 1250-LTC may be ordered with isolated synchro input terminals. In cases where there is a compromise of the (Controller, SCADA, etc…) analog input’s isolation to earth ground, this Isolation Option will prevent AC voltage from becoming impressed upon the 1250-LTC’s analog output signal to that device. (See Note at the end of Section 3.1, page 39) This option consists of two signal isolation transformers installed in the signal input circuitry. Performance and reliability are not affected when this option is installed.

Please note that this option is not compatible with the Relay Option (-R). The “-I” and “-R” options can not be installed simultaneously. They occupy the same space inside the instrument. You must choose one or the other.

4.0 FIELD CALIBRATION & TEST

Calibration: The Model 1250-LTC should not require field calibration. However, there are provisions in the menu to facilitate Signal Input Calibration and Analog Output Calibration. Signal Input Calibration cannot be performed in the field; it is strictly an infactory function. The analog output may be adjusted in the field. A calibrated multi-meter should be used to measure the output signal during calibration.

To enable analog calibration, select the OP 30, CAL menu command and choose the “On” mode. If you are using the RS-232 serial port, use the ANACAL command. The analog output may be forced to LOW, MID, and HIGH output signal states.

If menu commands are being used, select the OP 31, L CAL command to force the analog output to LOW scale output. If you are using the RS-232 serial port, press the space bar on the computer terminal. This toggles the output between LOW, MID, and HIGH outputs. The display on the 1250-LTC should read “LO”. The analog output low scale may now be adjusted by turning the “ZERO” pot, accessible through the slot in the left side of the case (see Figure 4.1), until the output signal is reading properly on the multi-meter.

If menu commands are being used, select the OP 32, H CAL command to force the analog output to HIGH scale output. If you are using the RS-232 serial port, press the space bar on the computer terminal. The display on the 1250-LTC should read “HI”. The analog output high scale may now be adjusted by turning the “SPAN” pot (see Figure 4.1) until the output signal is reading properly on the multi-meter. Repeat analog LOW and HIGH calibration steps several times to assure proper output signal calibration of both. Some interaction may occur between the ZERO and SPAN adjustments.

If menu commands are being used, select the OP 33, D CAL command to force the analog output to MID scale output. If you are using the RS-232 serial port, press the space

bar on the computer terminal. The display on the 1250-LTC should read “--”. The analog output should read a mid-scale signal on the multi-meter. There is no adjustment for this midscale output.

Figure 4.1 Analog Output Adjustment Pots

Self-Diagnostic Tests: The Model 1250-LTC regularly performs a number of selfcheck diagnostic tests and generates error codes in the form “FA n” and “ERR n” if it detects an internal fault. The “n” number indicates the type of failure detected. See Section 5.0, page 50, for a full list of error codes and their explanation.

Power Fail: The 1250-LTC is designed to shut its microprocessor off when it detects the line voltage falling below a fixed threshold, typically 85 to 105 / 170 to 210 VAC. This feature enables the microprocessor to properly store its data before the power is lost completely. The 1250-LTC will automatically re-start itself when the line voltage rises above the Power Fail Threshold voltage.

The software revision number can be displayed by pressing the “SELECT/ENTER” key while turning on the power to the 1250-LTC.

The 1250-LTC has the capability to delete all user-programmed values and restore all factory default program values. This “cold boot” is accomplished by pressing the “MENU” key while turning on the power to the 1250-LTC. There is no way to undo the effects of a cold boot.

The LED display can be tested. Use the OP 40, LED t, LEDTEST command to turn

on all display LED’s. Press the ENTER key to stop the test.

The RS-232 port can be tested. Use the OP 41, RS t menu command to enter the RS-232 Echo Test mode. With a computer terminal connected to the serial port, type in some characters. The 1250-LTC should receive these characters and re-transmit them back to the terminal. The characters typed should appear on the terminal display. Press the ENTER key to stop the test.

The High / Low relays can be tested. Use the OP 43, RLY t, RLYTEST command to turn on one of the relays. The UP and DOWN keys will cause the 1250-LTC to toggle between the High and Low relay. If you are using the RS-232 serial port, press the space bar on the computer terminal to toggle between the High and Low relay.

5.0 ERROR CODES

Table 5.1 Error Codes

DISPLAY DESCRIPTION

FA 2

FA 3

FA 5

FA 20

FA 22

FA 25

FA 27

ERR 30

ERR 80

LOtAP

HItAP

ttCLt

OtGLt

udCLt

PtnLt

1dCLt

* This alarm needs to be reset, either manually or automatically. Use the OP 53, Aut25, AUTO25 command to set the Automatic Reset to “On” or “Off”. When the Automatic Reset

is set to “Off”, press the MENU button to manually reset the alarm.

** This alarm needs to be reset, either manually or automatically. Use the OP 60, Aut27, AUTO27 command to set the automatic reset to “On” or “Off”. When the Automatic Reset is set to “Off”, press the MENU button to manually reset the alarm.

Watchdog Re-start (Processor Crash If condition recurs, call the factory.) Memory Error at start-up (User programming is erased, factory program defaults are re-loaded.)

Keyboard Error at start-up (UP or Down Key, or more than one key is being pressed during power-up.) Input Calibration Error (Input signal differential too large. Factory use only) Internal Timer Failure (Call the factory.) Synchro input signal not present * (Measure voltages at terminals A-C and B-C.) Synchro input signal is not stable - never stops changing ** (The LTC is repeatedly changing taps, or there is noise present on the signal.) Analog output calibration mode not enabled (Change OP 30 to “On”.) Serial Port Parameter Conflict (Change Stop Bits or Parity setting.)

Alarm condition: the Low Tap position limit has been reached. (The LTC position is lower than the Low Tap alarm limit.) Alarm condition: the High Tap position limit has been reached. (The LTC position is higher than the High Tap alarm limit.) Alarm condition: the Total Tap Change counter limit has been reached. (There have been too many tap changes – total Up and Down.) Alarm condition: the On-Tap Guard band limit has been reached. (One or more tap changes have stopped outside the acceptable position limit.) Alarm condition: the Up-To / Down-To tap change counter limit has been reached. (There have been too many changes up or down to one or more taps.) Alarm condition: the Pass Through Neutral limit has been reached. (There have been too many days without a Pass Through Neutral.) Alarm condition: the One Direction tap change counter limit has been reached. (There have been too many consecutive tap changes in one direction.)

6.0 SPECIFICATIONS

(All values are typical, unless otherwise specified)

ENCLOSURE: RECTANGULAR PANEL MOUNTED INSTRUMENT MATERIAL PLASTIC SIZE 89mm W X 41.3mm H X 178mm D BEZEL 112mm W X 62mm h X 17.5mm D MOUNTING INTEGRAL SNAP-IN TABS

POWER INPUT: CONNECTOR SCREW TERMINALS L1, L2, GND VOLTAGE 115 VAC +/- 10% OPTIONAL 230 VAC +/- 10% FREQUENCY 47 TO 63 Hz POWER CONSUMPTION 8 VA MAX FUSE INTERNAL (3/8 AMP) ISOLATION TRANSFORMER (1000 VAC)

TEMPERATURE RANGE OPERATING 0 TO 55 DEG. C

DISPLAY 5 DIGIT, 7 SEGMENT LED WITH SIGN

0.56 INCH HEIGHT FOUR STATUS INDICATOR LED’S VIEWING DISTANCE 23 FEET UPDATE RATE 10 TIMES PER SECOND ACCURACY (25 DEG. C) +/- 10 ARC MINUTES W/ TYPICAL SYNCHRO

RESOLUTION 6 ARC MINUTES

TEMPERATURE DRIFT +/- 0.2 ARC MINUTES PER DEG. C WITH

TYPICAL SYNCHRO

ELECTRICAL INPUTS

SIGNAL INPUT 3 PHASE, 0 TO 90 VAC

(

PROGRAM DISABLE CONNECT TERMINAL #3 TO #4

ELECTRICAL OUTOUTS OPTIONAL HI/LO RELAYS 2 ea. FORM 1A N.O. 3A @ 250 VAC (RESISTIVE)

1/10 HP @250VAC 3A @30 VDC (RESISTIVE) TOTAL ISOLATION 1000 VAC

ANALOG OUTPUT RESOLUTION 12 BITS (+/- 0.025% OF F. S.) NON-LINEARITY +/-0.1% OF FULL SCALE

INPUT ISOLATION OPTIONAL)

Model 1250-LTC Installation & Programming Manual

Incon 1250-LTC Installation And Programming Manual

Specifications and Main Features

Frequently Asked Questions

User Manual