Omega Products LDP6-CDC4 Installation Manual
LDP6-CCDC4
MODBUS Communication Option Card
M4540-0607
LP0686X
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, only handle the cards by the edges. 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 scewdriver 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
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.
6. See manual for wiring connections and programming procedures.
DESCRIPTION
This product bulletin covers the MODBUS Communication Card for the
PTC9, DPF93, and the LDP6 family of meters. The card will allow the Meter to
transmit Display Values, Setpoints and Reset Values via
MODBUS RS485
communication, in the RTU and ASCII modes.
TOP VIEW
MODBUS SPECIFICATIONS
1. Type: RS485; RTU and ASCII MODBUS modes
2. Isolation To Sensor & User Input Commons: 500 Vrms for 1 minute.
Working Voltage: 50 V. Not isolated from all other commons.
3. Baud Rates: 300 to 38400.
4. Data: 7/8 bits
5. Parity: No, Odd, or Even
6. Addresses: 1 to 247.
7. Transmit Delay: Programmable; See Transmit Delay explanation.
INSTRUCTION
SHEET
Shop online at: omega.com e-mail: info@omega.com
For latest product manuals: omegamanual.info
2
SERIAL SET-UP DIP SWITCH OPERATION
Serial port configuration is accomplished through two banks of DIPswitches
on the
MODBUS card. The bank of 8 switches sets the Unit Address, the bank
of 7 switches sets the Serial port parameters (ASCII/RTU, 7/8 bits, Parity, and
Baud rate). Changes to the switch settings are only detected on power-up of the
unit. After changing a switch setting, power to the unit must be cycled for the
new switch setting to take effect.
Both unit address and serial set-up are set via DIP switches on the
MODBUS
option card. See the DIP switch setting table for more details on these
DIP switches.
For the Unit Address bank, the high order bit is switch 1, and the ON
position is a ‘1’, the OFF position is a ‘0’. Legal unit addresses are 1 to 247.
When a Unit Address of 0 is selected, the card responds to Unit Address 1.
When a Unit Address of 248 through 255 is selected, the card responds to Unit
Address 247.
For the serial bank, the following settings apply:
BAUD RATE SWITCH SELECTIONS
SWITCH SETTINGS AVAILABLE
RTU1 OFF: ASCII ON: RTU
8 Bits2 OFF: 7 Bits ON: 8 Bits
No Parity3 OFF: None ON: Parity
OFF4 OFF: Even ON: Odd
5 Baud Rate
9600
6 Baud Rate
(See Baud Rate
Switch Selections)
7 Baud Rate
⎫
⎬
⎭
5 6 7
38400: ON ON ON
19200: ON ON OFF
9600: ON OFF ON
4800: ON OFF OFF
2400: OFF ON ON
1200: OFF ON OFF
600: OFF OFF ON
300: OFF OFF OFF
FACTORY
SETTINGS
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 same pair of wires is used to both transmit and receive data.
RS485 is therefore always half-duplex, that is, data cannot be received and
transmitted simultaneously.
The LDP6-CDC40 MODBUS communication option card returns different
values for both register and coil values dependent on the type of meter the card
is used with. The three types of meter are:
METER TYPE DEFINITION
METER TYPE MODELS
Analog
Digital DPF9300, LDPF63000, LDPF63100
Timers PTC900, PTC901
DP63500, DP63600, DP63700, DP63800,
DP63900, LDP63000, LDP63100
(CSR) Control Status Register [40021] (Analog)
The Control Status Register is used to directly control the meter’s outputs
(setpoints and analog output), or view the state of the setpoint outputs and the
status of the temperature sensor (DP63500 only). The register is bit mapped with
each bit position within the register assigned to a particular control function. The
control functions are invoked by writing to each bit position. The bit position
definitions are:
In Manual Mode, the setpoint outputs are defined by the values written to bits
b0, b1, b2, b3; and the analog output is defined by the value written to the AOR.
Internal control of these outputs is then overridden. In automatic mode, the
setpoint outputs can only be reset off.
(MMR) Auto/Manual Mode Register [40036] (Digital/Timer)
This register sets the controlling mode for the outputs. In Auto Mode (0) the
meter controls the setpoint output. In Manual Mode (1) the outputs are defined
by the registers SOR. When transferring from auto mode to manual mode, the
meter holds the last output value (until the register is changed by a write). Each
output may be independently changed to auto or manual. Select values to place
in manual mode by writing appropriate value to holding register 40036. The bit
position definitions are:
Examples:
1. Select manual mode for all outputs and AOR:
Value to write to holding register 40036: 001Fh
(SOR) Setpoint Output Register [40038] (Digital/Timer)
This register is used to view or change the states of the setpoint outputs.
Reading from this register will show the present state of all the setpoint outputs.
A “0” in the setpoint location means the output is inactive and a “1” means the
output is active.
In Automatic Mode (See MMR Description), the meter controls the setpoint
output state. In Manual Mode, writing to this register will change the output
state. The bit position definitions are:
Examples:
1. Turn all outputs on:
Value to write to holding register 40038: 000Fh.
2. Turn outputs 1, 3 on:
Value to write to holding register 40038: 0005h.
3. Turn all outputs off:
Value to write to holding register 40038: 0000h.
(AOR) Analog Output Register (Not Timer)
The Analog Output Register controls the analog output of the meter. The
manual mode must first be engaged by setting bit 4 of the CSR (Analog) or bit
0 of the MMR (Digital). The range of values of this register is 0 to 4095, which
corresponds to 0 mA, 0 V and 20 mA, 10 V; respectively. If a value larger than
4095 is written to the AOR register, 4095 will be loaded. The table lists
correspondence of the output signal with the register value.
*Due to the absolute accuracy rating and
resolution of the output card, the actual
output signal may differ 0.15% FS from
the table values. The output signal
corresponds to the range selected (20 mA
or 10 V).
Writing to this register while the meter is in the manual mode causes the output
signal to update immediately. While in the automatic mode, this register may be
written to, but the output will not update until the meter is placed in manual mode.
Examples:
1. Set output to full scale:
Value to write to holding register 40020 (Analog) or 40037 (Digital):
0FFFh (4095).
2. Set output to zero scale:
Value to write to holding register 40020 (Analog) or 40037 (Digital): 0 0 00h (0).
3
MODBUS SUPPORTED FUNCTION CODES
COIL FUNCTIONS
FC01: Read Coils
FC05: Force Single Coil, FC15: Force Multiple Coils.
1. Valid coil addresses are 1-49.
2. Block starting point can not exceed coil 49.
HOLD REGISTER FUNCTIONS
FC03: Read Holding Registers.
FC06: Preset Single Register, FC16: Preset Multiple Registers.
1. Valid register address are 40001 – 40039, 40041, 40042, 41001 – 41010.
2. Up to 16 registers can be requested at one time.
3. Block starting point can not exceed the register boundaries.
4. Holding registers are a mirror of Input registers (FC04).
5. Unused registers will return a value of HEX <8000>.
6. If a register is implemented, but does not exist for a particular unit
configuration (such as SP3, SP4) a value of HEX <0000> will be returned.
7. Registers 41001 – 41010 contain the slave ID. See FC17.
8. Broadcast write is supported for FC06 & FC16. Register writes using address
“0” will be recognized by the
MODBUS card, regardless of address DIP
switch setting.
OTHER SUPPORTED FUNCTIONS
FC04:
Returns the same values as FC03, except the register number starts with “3”
(Ex: Input Hi is 30001)
FC08 – Fetch Comm. Event Counter.
The MODBUS response breaks down as follows:
“:010804”<TOT HI><TOT LO><GOOD HI><GOOD LO>XX<CR><LF>
The “TOT HI” and “TOT LO” values are the total number of messages that
were received, that started with the card’s address. The “GOOD HI” and
“GOOD LO” are “good” messages (correct address, parity, and checksum). The
values are reset on power up and every time the FC08 function is requested.
FC17 - Report Slave ID.
The following is sent upon FC17 request:
Unit Address, 17 (FC code), RLC-PAX(I or ?) 00?0, 0100 (for code version
1.00), 16 (number of read supported registers), 16 (number of write
supported registers), 00 (number of registers available for GUID/Scratch pad
memory), checksum of the string.
The following is the HEX of a DPF93 (with unit address of 247):
:<F7><11><14><52><4C><43><2D><50><41><58><49><30><30><3F>
<30><01><00><00><10><00><10><00><00><XX><CR><LF>
XX is the LRC Checksum
Register Value
V (V)
Output Signal*
0 0.0000.000
1 0.00250.005
2047 5.00010.000
4094 9.997519.995
4095 10.00020.000
I (mA)
MANUAL MODE DESCRIPTION
1 = manual mode
0 = automatic mode
bit 4: Manual Mode
bit 3: SP4 Output
bit 2: SP3 Output
bit 1: SP2 Output
bit 7: Always stays 0, even if 1 is sent.
1 = sensor fail
0 = sensor normal
bit 6: Sensor Status (DP63500 only)
bit 5: Always stays 0, even if 1 is sent.bit 0: SP1 Output
0 = output off
1 = output on
⎫
⎬
⎭
bit 0: SP1
bit 1: SP2
bit 2: SP3
bit 3: SP4
⎫
⎬
⎭
0 = Output off
1 = Output on
bit 0: SP4
bit 1: SP3
bit 2: SP2
bit 3: SP1
⎫
⎬
⎭
0 = Auto Mode
1 = Manual Mode
TIMER
bit 0: Analog Output
bit 1: SP4
bit 2: SP3
bit 3: SP2
bit 4: SP1
⎫
⎬
⎭
DIGITAL
0 = Auto Mode
1 = Manual Mode
Loading...