MEDACS DATA SHEET


	Smart Configurable Single or Dual Channel Galvanic Isolation Universal or Frequency Input mA and Relay Output Remote I/O via RS485 OPC Compliant Easily Customized via TFML Unique "Bus Jumper" System
DIN RAIL SIGNAL CONDITIONERS, WITH TFML MEDACS II
DESCRIPTION The MEDACS II is a totally new concept in DIN rail signal conditioners. It consists of a family of modules that allow the user to select the input and output. Two basic input modules are available. The 2100 and 2200 series universal input units accept RTDs, TC, mA and DC volts. The 2300 and 2400 series accept frequency inputs. Output options include isolated 4-20 mA, single SPDT relay and dual N/C relays, in various combinations. All units have RS485 Modbus serial communication which is used in conjunction with our M-Config software to configure the modules. The M-Config software is loaded into a PC and communication to the MEDACS is established through a comms port on the PC. This usually requires an RS232 to RS485 converter that is optionally available. The software program is very easy to use and intuitive using pull down menus and dialog boxes. Single channel units have a built-in keypad and digital display that can also be used to configure the units. More than 50 points of linearization can be programmed into the modules either via RS485 or by using the keypad on the single channel modules. Polynomials can also be programmed into the conditioners using RS485. In addition more complex functions can be programmed using our TFML.

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About Remote I/O
Modbus
Modbus is a master-Slave protocol. This means all communications are initiated by the Master device (ex. Computer, PLC, DCS) and in general the Master communicates with one Slave device (ex. MEDACS II) at a time.

The RS485 mode determines the way that the network is connected together. The MEDACS II can be configured in either the 2-wire or 4-wire mode shown above. The 2-wire arrangement has both transmit and receive signals. In comparison, the 2-wire mode makes the most efficient use of wire and connections while the 4-wire mode has the advantage of not relying on critical timing from the Master device.

The MEDACS II further simplifies installation of either a 2-wire or 4-wire system by using a unique Bus Jumper system which eliminates both the typical RS485 and power wiring from unit to unit.

Multi-Drop and Device Addresses
The MEDACS II comes standard with one-to-one RS485 communications which allows the Master to be wired to and communicate with one Slave. With optional Multi-Drop Communications, the Master can be connected to and communicate with up to 32 Salves. This allows the Master to identify, transmit and receive information from each specific slave.

Gateways
Although each unit is equipped with an RS485 serial interface which can connect directly to a Modbus network, up to 64 channels can be connected to a gateway module. Gateways provide the physical layer and protocol conversion to common communication bus systems such as Ethernet, Profibus, Foundation Fieldbus etc.
Contact the Sales Office for details about Gateways and their current availability.

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About OPC
Managed by the OPC Foundation, OPC (Object linking and embedding for Process Control) is an industry standard created with the collaboration of a number of leading worldwide automation and hardware/software suppliers working in cooperation with Microsoft. The MEDACS II is designed to meet the OPC requirements.

The goal of this standard "Plug-and-Play". By using the standard OPC client-server model, any OPC-compliant device (like the MEDACS II) will quickly, easily and seamlessly connect to another and immediately work without the need for lengthy installation procedures. The user can then concentrate more on the chosen client software package (e.g. DCDS, SCADA, HMI, Plant Scheduling) rather than the problems of system integration.

The application of the OPC standard interface makes possible interoperability between automation/control applications, field system/devices and business/office applications.

Hardware Platform
The minimum hardware requirement to run OPC are IBM compatible PC:

P100 processor or higher
64Mb Ram
200Mb free disk space
Microsoft Windows
95 (SR2) / 98 / NT4 / 2000

SELF DOCUMENTATION
Thanks to the digital nature of MEDACS II transmitters, self-documentation (not feasible with earlier analog transmitters) becomes possible. In addition to the standard configuration data stored within the transmitter, are data related to the instrument itself such as Manufacturer, Part No., Serial No. ,Software Revision No., Date (which can be used to advise when re-calibration is required), Final Assembly No. and Sensor Serial No. A 32 character message facility enables additional information, such as the name of the engineer who last serviced the instrument, to be recorded within the instrument itself.

By using the appropriate software tools, a complete device history can be maintained automatically thus ensuring cost savings and reduced downtime due to better programming maintenance.


Current Input
Base Accuracy	0.05% FS ±0.05% of reading
Thermal drift	300ppm/°F
Input impedance	20Ω
Linearization	Linear, Square root, Power 3/2, Power 5/2, Custom
Two isolated and regulated 19V power supplies are available to power the current loops, and are capable of sourcing 24mA for each channel.

RTD Inputs
Sensor Range	-328 to 1,562°F
Linearization	BS EN 50751 / JISC 1604 / Custom
Basic accuracy	0.2°F ±0.05% of reading
Thermal drift (zero)	±0.006Ω /°F
Thermal drift (span)	200ppm /°F
Excitation current	300mA to 550mA
Lead resistance effect	0.004°F/Ω
Max. lead resistance	50Ω/leg

Thermocouple Inputs
Type	Range (°F)
......K	-328°F	to	2,498°F
......J	-328°F	to	2,192°F
......T	-328°F	to	752°F
......R¹	-15°F	to	3,200°F
......S¹	-15°F	to	3,200°F
......E	-328°F	to	1,832°F
......F	-148°F	to	1,112°F
......N	-292°F	to	2,306°F
......B²	-15°F	to	3,002°F
Custom	-1,999	to	9999
Accuracy	±0.04% FS ±0.04% of reading or ±0.5°F, whichever is greater
Linearization	BS4937 / IEC 584-3 / Custom
Cold junction error	±0.050°F
Cold junction tracking	0.1°F/°F
Cold junction range	-4°F to 158°F
Thermal drift	zero 6µV/°F
	span 300PPM°F
Notes: 1. Accuracy true for 1,472°F to 3,200°F 2. Accuracy true for 752°F to 3,002°F

Voltage Inputs
Range	±10mV, ±5V, ±10V, 1-5V
Accuracy	0.04% FS ±0.04% of reading
Thermal drift	330ppm/°F
Input impedance	1MΩ
Linearization	Linear, Square root, Power 3/2, Power 5/2, Custom

Frequency Inputs
A wide range of input types and frequencies can be accommodated without the need for Switches or Jumpers. Totalize functions can be achieved via TFML.
Input Types	Namur, Low Voltage (>10mV), TTL, Open Collector, PFC
Frequency range	0.1Hz to 10KHz
Accuracy	0.003% FS

Digital Inputs
Single channel units can also accept two external digital inputs which can be TTL, Open Collector, 24VDC Logic or Potential Free Contacts. Dig 1 is dedicated to a reset/clear function enabled by the configuration software while Dig 2 is reserved for use with TFML. Both digitals can be read via the communications and used to signal events.

Two output option types are available per channel, relay or current retransmission. The configuration of these will vary depending upon whether they are fitted on the single or dual channel transmitter.
.Current Retransmission Outputs
.Output Range
.Single Channel	.0-10, 0-20, 4-20mA source or sink
.Dual Channel	.4-20mA sink
.Maximum current output	.<23mA
.Accuracy	.0.07% or 5µA, whichever is greater
.Max. power supply	.30V (In SINK mode)
.Temperature stability	.8µA/°F
Note: Max. source load 750R

Relay Outputs
Two relay options are available, either a single changeover or twin independent relays with Normally closed contacts.¹
Alarm Action	Off, High, Low, Deviation, Test
Hysteresis	Programmable 0 to 100%
Delay Time²	Programmable
Start-up Delay	Programmable
	......AC	......DC
Max. switching voltage	48V RMS	48V
Max. current	1A @ 48V	1A @ 30V
Max. power	60VA	30W
Contact resistance	<100mΩ
Electrical life @ full load	100,000 operations
Mechanical life	10,000,000 operations
Notes:
Contacts are Normally Closed i.e. the contact is closed at power off and when operating in an alarm condition. The contact opens in the absence of an alarm condition. The active function can be reversed in the software. Alarms must be continuously present for this period in order to be recognized.

Response Time	300mSec
Filter	Programmable or Adaptive
Power Requirements	24V DC ±10% @ 200 mA
Isolation	500V AC I/P-O/P-PSU
Ambient operating range	-22 to 140°F
Ambient storage	-58 to 185°F
Ambient humidity	10 to 90% RH
EMC emissions	BS EN50081-1
EMC immunity	BS EN50082-2
Display Range	-1999 TO 9999

.Model & Input Code
....MEDACS 21 ... ..One Universal Input (with Display, Keys & 2 discrete inputs) .MEDACS 22 ... ..Two Universal Inputs .MEDACS 23 ... ..One Frequency Input (with Display, Keys & 2 discrete inputs) .MEDACS 24 ... ..Two Frequency Inputs
.Outputs Code		Output 1	Output 2
00		None	None
11	(not available on MED 21 & MED 23)	Current	Current
13	(not available on MED 24)	Current	Twin N/C
22		C/O Relay	C/O Relay
33		Twin N/C	Twin N/C
.Modbus Multi-Drop Serial Communications Option Code
00	..........Standard One-to-One RS485 Serial Communications
MD	..........Modbus Multi-Drop RS485 Serial Communications Upgrade ..........(Including M-Config and CD Manual)

Universal Input Overview
.....Sensor	.....Range
.....mA	.....4-20, ±20, ±10
.....RTD	.....Pt100, Ni120
.....T/C	.....K, J, T, R, S, E, N, F, B
.....Volts	.....±0.1, ±10, ±5, 1-5

Each MEDACS 2000 module comes supplied with RS485 serial communications using MODBUS rtu protocol as standard:
Baud rate	19.2KB, 9.6KB or 1.2KB
Mode	2-wire or 4-wire available
Device Address	Network unique address 1-255
Note: Maximum device number for Modbus is 247.