Red Lion PAXCDC1,2 User Manual
Finger
Hold
Finger
Hold
Serial
Communications
Card
Setpoint
Output
Card
Alignment
Slots
Connectors
Main
Circuit
Board
Analog Output
or
Real-Time
Clock Card
ANALOG
OUTPUT OR
REAL-TIME
CLOCK CARD
SETPOINT
OUTPUT
CARD
LABEL
SERIAL
OUTPUT
CARD
LABEL
MAIN
LABEL
LABEL
Bulletin No. PAXCDC-F
Drawing No. LP0402
Released 07/10
Tel +1 (717) 767-6511
Fax +1 (717) 764-0839
www.redlion.net
MODEL PAXCDC -SERIAL COMMUNICATIONS PLUG-IN OPTION CARDS
DESCRIPTION
This bulletin serves as a guide for the installation, configuration and
operation of the RS232 and RS485 cards for the PAX family of meters. Only
one communication card can be used at a time.
INSTALLING AN OPTION CARD
Caution: The option and main circuit cards contain static sensitive
components. Before handling the cards, discharge static charges
from your body by touching a grounded bare metal object. Ideally,
handle the cards at a static controlled clean workstation. Also,
handle the cards by the edges only. Dirt, oil or other contaminants
that may contact the cards can adversely affect circuit operation.
Warning: Exposed line voltage exists on the circuit boards. Remove
all power to the meter AND load circuits before accessing the unit.
1. Remove the main assembly from the rear of the case. Squeeze the finger
holds on the rear cover, or use a small screwdriver to depress the side
latches to release it from the case. It is not necessary to separate the rear
cover from the main circuit card.
2. Locate the option card connector for the type of option card to be installed.
Hold the unit by the rear connector, not the display board, when installing
an option card.
3. Install the option card by aligning the option card connector with the slot
bay in the rear cover. The cards are keyed by position with different main
board connector locations. Be sure the connector is fully engaged and the
tab on the option card rests in the alignment slot on the display board.
4. Slide the assembly back into the case. Be sure the rear cover latches fully
into the case.
5. Apply the option card label to the bottom side of the meter. Do not cover
the vents on the top surface of the meter . The surface of the case must be
clean for the label to adhere properly. Apply the label to the area designated
by the large case label.
The PAX meter can be fitted with up to three different option cards. The slot
bays of the option cards are dedicated to a particular card function. The option
card functions are: serial communications, analog output and setpoint output.
Only one card from each function category can be installed into the meter.
TOP VIEW
ORDERING INFORMATION
MODEL NO. DESCRIPTION PART NUMBER
RS485 Serial Communications Output Card with
Terminal Block
Extended RS485 Serial Communications Output
PAXCDC
1
Card with Dual RJ11 Connector
RS232 Serial Communications Output Card with
Terminal Block
Extended RS232 Serial Communications Output
Card with 9 Pin D Connector
PAXCDC10
PAXCDC1C
PAXCDC20
PAXCDC2C
12
TXD
RXD
COMM.
PAX METER (DTE)
RECEIVING DEVICE
2
NC
RXD
TXD
3
32
75
5
DTE
3
2
DB9
13
14
15
DTEDCE
DB25DB25
1
5
9
6
PIN 3 RXD
PIN 5 COMMON
FEMALE
PIN 2 TXD
12
B(-)
33K
33K
+5V
Transmit
Enable
PAX METER
RECEIVING DEVICE
A
(+)
COMM.
*
NC
*
OPTIONAL
13
14
15
SPECIFICATIONS
PAXH Isolation For Both Cards:
Isolation To Sensor Common: 1400 Vrms for 1 min.
Working Voltage: 125 V
Isolation To User Input Common: 500 Vrms for 1 min.
Working Voltage: 50 V
RS485 Communication Card
Type: RS485 multi-point balanced interface
Isolation To Sensor & User Input Commons: 500 Vrms for 1 min.
Working Voltage: 50 V. Not Isolated from all other commons.
Baud Rate: 300 to 19.2k
Data Format: 7/8 bits; odd, even, or no parity
Bus Address: 0 to 99, max 32 meters per line
Transmit Delay: Selectable; 2 - 50 msec or 50 - 100 msec
RS232 Communication Card
Type: RS232 half duplex
Isolation To Sensor & User Input Commons: 500 Vrms for 1 min.
Working Voltage: 50 V. Not Isolated from all other commons.
Baud Rate: 300 to 19.2k
Data Format: 7/8 bits; odd, even or no parity
WIRING CONNECTIONS
RS232 Communications
RS232 is intended to allow only two devices to communicate over distances up
to 50 feet. Data Terminal Equipment (DTE) transmits data on the Transmitted
Data (TXD) line and receives data on the Received Data (RXD) line. Data
Computer Equipment (DCE) receives data on the TXD line and transmits data on
the RXD line. The PAX emulates a DTE. If the other device connected to the
meter also emulates a DTE, the TXD and RXD lines must be interchanged for
communications to take place. This is known as a null modem connection. Most
printers emulate a DCE device while most computers emulate a DTE device.
Some devices cannot accept more than two or three characters in succession
without a pause in between. In these cases, the meter employs a busy function.
As the meter begins to transmit data, the RXD line (RS232) is monitored to
determine if the receiving device is “busy”. The receiving device asserts that it
is busy by setting the RXD line into a space condition (logic 0). The meter then
suspends transmission until the RXD line is released by the receiving device.
Terminal Block Connection Figure
Extended Comms Connection Figure
RS485 Communications
The RS485 communication standard allows the connection of up to 32
devices on a single pair of wires, distances up to 4,000 ft. and data rates as high
as 10M baud (the PAX is limited to 19.2k baud). The same pair of wires is used
to both transmit and receive data. An RS485 bus is therefore always half-duplex,
that is, data cannot be received and transmitted simultaneously.
PAX METER
+5V
Transmit
Enable
33K
33K
12
13
14
15
Terminal Block Connection Figure
Not used
Not used
PAX CONNECTOR
Not used
COMM
B-
A+
3542
Extended Comms Connection Figure
2
RECEIVING DEVICE
(+)
COMM.
NC
OPTIONAL
MODULE 7 - SERIAL COMMUNICATIONS PARAMETERS ()
7-SrL
PAR
bAUd
Baud Rate
It is necessary to match the PAX meter’s serial communications parameters
to the host’s parameters before communications can be established. This is
accomplished by using the PAX front panel keys to enter .
Indicates Program Mode Alternating Display.
Parameter
dAtA
Parity BitData Bit
Factory Settings are shown.
Selection/Value
PARAMETER MENU
PAr
Addr
Meter
Address
Abrv
Abbreviated
Printing
PAR
INP
Print
Input Value
Enter the serial node address. With a single unit on a bus, an address is not
needed and a value of zero can be used (RS232 applications). Otherwise, with
multiple bussed units, a unique address number must be assigned to each meter.
The node address applies specifically to RS485 applications.
tot
Print
Total Value
OPt
Print
Options
HILO SPNt
Print
Max & Min
Values
METER ADDRESS
to
NO
YES
Print
Setpoint
Values
Pro
BAUD RATE
DATA BIT
PARITY BIT
Set the baud rate to match that of other serial communications equipment.
Normally, the baud rate is set to the highest value that all of the serial
communications equipment is capable of transmitting.
Select either 7 or 8 bit data word lengths. Set the word length to match that
of other serial communication equipment. Since the meter receives and
transmits 7-bit ASCII encoded data, 7 bit word length is sufficient to request
and receive data from the meter.
Set the parity bit to match that of the other serial communications equipment
used. The meter ignores the parity when receiving data, and sets the parity bit
for outgoing data. If no parity is selected with 7-bit word length the meter
transmits and receives data with 2 stop bits. (For example: 10 bit frame with
mark parity)
ABBREVIATED PRINTING
PRINT OPTIONS
Select abbreviated transmissions (numeric only) or full field transmission.
When the data from the meter is sent directly to a terminal for display, the extra
characters that are sent identify the nature of the meter parameter displayed. In
this case, select . When the data from the meter goes to a computer, it may be
desirable to suppress the node address and mnemonic when transmitting. In this
case, set this parameter to .
- Enters the sub-menu to select those meter parameters to appear in the
block print. For each parameter in the sub-menu select for the parameter to
appear with the block print, and to disable the parameter.
*Setpoints 1-4 are setpoint plug-in card dependent.
Input Value
Max and Min Values
Total Value
Setpoint values*
3
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