SOLID STATE INSTRUMENTS RTR-2C C Series High Speed Pulse Isolation Relay Instructions

SOLID STATE INSTRUMENTS RTR-2C C Series High Speed Pulse Isolation Relay

HIGH SPEED PULSE ISOLATION RELAY INSTRUCTION SHEET

MOUNTING POSITION – The RTR-2C may be mounted in any position.
POWER INPUT – Connect the “Hot” lead to the L1 terminal. The power supply is autorunning from 120 to 277VAC. Connect the Neutral power supply lead to the NEU terminal. Connect the electrical system ground to the GND terminal. The unit must be grounded for proper operation.
METER CONNECTIONS – The RTR-2C’s Kin and Yin terminals are connected to the meter. The RTR-2C’s Yin terminal is the “pulled-up” +13VDC source which is connected to the “+” input of the meter. The Kin terminal is the system common return or ground. Upon a closure of the meter’s pulse switching device, the +13VDC Yin input line is pulled down to ground. The Amber LED will light indicating that a pulse has been received. If the width of the input pulse is very short, the Amber LED may be difficult to see. Assuming the pulse meets the input criteria, the Green LED will light, indicating that a pulse output switch has closed, and thus a pulse output has occurred. Shielded cable is highly recommended between the meter and the RTR-2C input.
FUSES – The fuses F1 and F2 are type 3AG and may be up to 1/10 Amp in size. Two 1/10 Amp fuses are supplied standard with the unit unless otherwise specified.
INPUT and OUTPUT CONFIGURATION – Under the RTR-2C’s cover in the center of the board just below the lower fuse (F1) is a 8-position DIP switch labeled S1. This DIP switch allows the input and output timing configurations to be set. Switch #1 sets the Normal or Fixed output mode. Use the Normal mode to have the output pulse length match the input pulse length. The normal mode is generally necessary for high speed and the length of the pulse varies with pulse speed. Use the Fixed mode for a fixed output pulse width. Switches S5, S6 and S7 set the input filtering time. Any pulse less than the selected input filtering time will be ignored and considered to be noise. Switches S2, S3 and 4 set the output pulse width if the Fixed mode is selected.
TEST MODE – The RTR-2C includes a test mode to be able to detect very short width input pulses. Enable the test mode by putting Switch 8 of S1 in the UP position. In this position, once a pulse is detected, it will latch on the RED LED to indicate that a pulse has been detected. Cycle the power to reset the LED. The test mode will detect pulses down to 25 microseconds. Put Switch 8 in the DOWN position for normal operation and reset the RED LED.
See page 3 &4 of this sheet for additional information on selecting system settings. Transient suppression for the contacts of the solid state relay is provided internally.

SOLID STATE INSTRUMENTS
a division of Brayden Automation Corp.
6230 Aviation Circle, Loveland Colorado 80538
Phone: (970)461-9600
E-mail:support@brayden.com

WORKING WITH THE RTR-2C RELAY

BLOCKING NOISE: The RTR-2C has a built-in noise rejection software algorithm for detecting valid pulses from a sending source.
The algorithm accomplishes this by measuring the time the input pulse is present. If the input pulse is present for less than the specified time (in milliseconds) as determined by the position of switches S1.5, S1.6 and S1.7, it is assumed to be noise. An input equal or longer in duration than the specified time is classified as a valid input and an output will occur. In the illustration to the left, the normal pulses with time durations of T1and T4 will cause an output. The short pulse of time duration T2 and the noise with duration T3 will be rejected because the length of time (pulse width) is too short, even though the voltage is of sufficient magnitude. The time T4 could be many times as long as T1 and it would still be a valid time pulse since it has met the minimum time requirement. The time duration of 20 milliseconds (max) has been chosen as the factory-set default value since one cycle of the 60 hertz AC line frequency represents 16.67 milliseconds. Most induced noise and arcing discharges do not last longer than this, while most contact closures are a great deal longer. The minimum filter time of the incoming pulse may be modified by changing switches S1.5, S1.6 and S1.7. See Table 2 on Page 3 for input filtering times.

OUTPUT PULSE DURATION: The RTR-2C can output two types of pulses – normal or fixed -depending upon the position of switch S1.1. In the UP position, the RTR-2C outputs a “fixed” pulse which has a duration determined by the position of switches S1.2, S1.3 and S1.4. Once a valid pulse has been qualified, the output pulse will be set and the specified output time will begin timing out. See Table 3 on page 3 for the selectable output pulse lengths. If switch S1.1 is in the UP position and the incoming pulse is of sufficient time duration to be a valid pulse, but is less than 100 milliseconds, for example, the output time period will still be 100 milliseconds. Thus, the RTR-2C can be used as a “pulse stretcher”. In the DOWN position, the RTR-2C outputs a “normal” (variable width) pulse which is the same duration as the valid input pulse. Thus, in fixed mode, the maximum pulse rate is dependent on the positions of switches S1.2 through S1.4. If no switches are switched up, the RTR-2C will default to the normal output mode, 20mS input time, and output will mirror the input pulse length.

CONFIGURING THE RTR-2C RELAY

OUTPUT MODE – Set the Output Mode to either the Normal (output pulse width equal to input time) or Fixed with Switch S1.1 as shown in Table 1.

Table 1

INPUT DEBOUNCE TIMES – The RTR-2C contains eight different input debouncing time options. A pulse received at the RTR-2C’s input must be present for at least the specified amount of time to be considered a valid pulse. Minimum pulse times can be set in the following times:
25uS,50uS,100uS, 200uS 500uS, 1mS, 5mS or 20mS. For most electric meter pulse applications, the 20mS input time will be satisfactory. For high-speed pulse applications with water or gas meters, the minimum input time may need to be reduced depending on the meter’s output pulse width. Table 2 below shows how to set switches S1.5 thru S1.7 for the selected time.

Table 2

CONFIGURING THE RTR-2C RELAY (con’t)

FIXED MODE OUTPUT PERIOD – When S1.1 is UP and selecting the fixed output pulse mode, the duration of the output time can be selected by using dip switches S1.2 thru S1.4. Output times are selectable as follows: 5mS, 10mS, 20mS, 50mS, 100mS, 200mS, 500mS and 1000mS. The receiving equipment may require pulses to be of a given minimum length to be considered a valid pulse. If input pulses are received while a fixed output pulse is timing out, the RTR-2C will store the received pulse(s) in an overflow register and output them as soon as the current pulse has timed out. The time between pulses is the same as the specified pulse time, giving a 50/50 duty cycle. A maximum of 65,535 output pulses can be stored. If the pulse rate from the meter is too high, pulses may be lost in the fixed mode if the output pulse register exceeds the 65,535 pulse maximum. In that case, the normal mode will have to be used. When in the operational mode, if stored pulses are present in the overflow register the RED LED will light.

Table 3

• Note: Switches S1.1-S1.8 come factory-set to the “DOWN” position.

TEST MODE – Set the Test Mode switch to either the operating mode or the test mode as indicated by Table 4.

Table 4

USING THE TEST MODE – Many water and gas meters have very high pulse rates with pulse durations or widths that are very short or narrow. Sometimes it is very difficult to observe pulses being received from the water or gas meter. To assist with detecting short pulses, the RTR-2C has a built-in test mode. The purpose of test mode is to detect a pulse from the meter and latch the RED LED on to let the installer know that a pulse has been received by the RTR-2C, even though it cannot be seen on the YELLOW LED since it’s on time is so short. Once the RTR-2C has detected a pulse and latched the RED LED on, dip switch S1.8 can be returned to the down position to reset the RED LED to off.

Alternately the RTR-2C can have its power cycled to reset the RED LED to continue monitoring for the next valid pulse.

In test mode, pulses continue to be processed and outputted.

RTR-2C Wiring Diagram

Water or Gas Meter Application

Brayden Autom ation Corp./Solid State I nstrum ents div.
6230 Aviation Circle
Loveland, CO 80538
(970)461-9600
support@brayden.com
www.solidstateinstruments.com

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