Red Lion GCM422 User Manual

1

! ALLOWS COMMUNICATIONS BETWEEN RS422 CONTROL

EQUIPMENT AND RLC PRODUCTS WITH 20 mA SERIAL
COMMUNICATIONS OPTION

! TRANSMIT DISABLE ALLOWS OPERATION ON A TWO-WIRE

BUS FOR RS485 COMPATIBILITY

! ISOLATED 20 mA SERIAL COMMUNICATIONS
! FULLY ENCLOSED SCREW TOGETHER DURABLE

PLASTIC CASE

DESCRIPTION

The GCM422 Serial Converter Module provides the capability of interfacing
Red Lion Controls products, with 20 mA current loop serial communications
option, to any equipment with RS-422 communications. The isolated 20 mA
current loop connections in the GCM422 allow multiple modules to be wired
into the serial loop. Data format of the RS-422 equipment must be the same as
the Red Lion Controls product (Reference the serial communications section of
the appropriate manual for more details). The GCM422 module can be made to
interface with RS-485 equipment by repositioning an internal jumper (which is
a removable plug type arrangement). (The user must supply a method of
electrically selecting the transmit disable input.)

An external power source is required to power the GCM422 module. Some
Red Lion Controls products have a +12 VDC output which can be used. (Note:

Reference appropriate manual to ensure +12 VDC output has enough current
capability.) The external power source and isolated 20 mA serial

communications loop connections are made via a 6 position terminal block
located inside the module. A 680Ω current limiting resistor is provided to obtain
the source current for the Serial Current Loop. Connections for the RS-422 or
RS-485 are made via a 25 pin female D-type connector.

SAFETY SUMMARY

All safety related regulations, local codes and instructions that appear in the
manual or on equipment must be observed to ensure personal safety and to
prevent damage to either the instrument or equipment connected to it. If
equipment is used in a manner not specified by the manufacturer, the protection
provided by the equipment may be impaired.

SPECIFICATIONS

1. POWER: +9 to 26 VDC @ 50 mA max. Power supplies must be Class 2 or

SELV rated.

2. RS-422 VOLTAGES:

Differential output voltage (pins 2 & 14): ±5 VDC

max.

under no load

condition.

Differential input voltage (pins 3 & 16): ±5 VDC

max.

mark condition = < -0.2 VDC
space condition = > 0.2 VDC

Common mode input voltage: -7 VDC to +12 VDC.

3. RS-485 TRANSMIT DISABLE INPUT (Pin 4):

Active low VIL= 0.8 VDC

max.

Internally pulled up to + 5 VDC through 3.3 KΩ resistor.

4. RS-422 DRIVE CAPACITY: Up to 32 RS-422 receivers connected in

parallel.

5. 20 mA CURRENT LOOP:
SO - Output Transistor Rating: V

max

= 25 VDC,

V

sat

= 1 VDC

max

@ 20 mA.

SI - Input Diode Rating: VF = 1.25 VDC

typ

, 1.5 VDC

max

@ 20 mA.

(Note: Reverse polarity protection at SI diode)

6. MAXIMUM CABLE LENGTH:
RS-422 or RS-485 cable: 4000 Ft.
20 mA current loop: 4000 Ft.

7. BAUD RATE: 9600 Baud max.

8. ENVIRONMENTAL CONDITIONS:

Operating Temperature: 0 to 50°C
Storage Temperature: -40 to 80°C
Operating and Storage Humidity: 85% max. relative humidity (non-

condensing) from 0°C to 50°C.

Altitude: Up to 2000 meters

9. CERTIFICATIONS AND COMPLIANCES:

SAFETY

IEC 1010-1, EN 61010-1: Safety requirements for electrical equipment for

measurement, control, and laboratory use, Part 1.

EMC EMISSIONS:

Meets EN50081-1: Residential, Commercial and Light Industry

CISPR 22 Radiated and conducted emissions

EMC IMMUNITY:

Meets EN 50082-2: Industrial Environment.

ENV 50140 - Radio-frequency radiated electromagnetic field

1

ENV 50141 - Radio-frequency conducted electromagnetic field

1

EN 61000-4-2 - Electrostatic discharge (ESD)

2

EN 61000-4-4 - Electrical fast transient/burst (EFT)

3

Notes:

1. For operation without loss of performance:

Install power line filter, RLC #LFIL0000 or equivalent.
I/O cables routed in metal conduit connected to earth ground.

2. Anti-static precautions should be observed before handling the device.

3. For operation without loss of performance:

Install power line filter, RLC#LFIL0000 or equivalent.

Refer to EMC Installation Guidelines section of the manual for additional

information.

10. DIMENSIONS:

0.99" (25.2 mm) H x 2.10" (53.4 mm) W x 4.32" (109.8 mm) L

11. Shielded cable must be used, connect shield drain wire to earth ground.

(Note: RS-485 Specifications are the same as RS-422)

MODEL GCM422 - SERIAL CONVERTER MODULE [RS422/20 mA current loop]

CAUTION:

Read complete instructions prior to

installation and operation of the unit.

Bulletin No. GCM422-G
Drawing No. LP0213
Released 2/05

Tel [phone]
Fax [phone]
www.redlion.net

ORDERING INFORMATION

MODEL NO. DESCRIPTION PART NUMBER

GCM422 Serial Converter Module RS422 GCM42201

2

EMC INSTALLATION GUIDELINES

Although this unit is designed with a high degree of immunity to
ElectroMagnetic Interference (EMI), proper installation and wiring methods
must be followed to ensure compatibility in each application. The type of
electrical noise, source or coupling method into the unit may be different for
various installations. In extremely high EMI environments, additional
measures may be needed. Cable length, routing and shield termination are
very important and can mean the difference between a successful or a
troublesome installation. Listed below are some EMC guidelines for
successful installation in an industrial environment.

1. DC power to the unit should be relatively clean and within the specified

limits. Connecting power to the unit from circuits that power inductive

loads that cycle on and off, such as contactors, relays, motors, etc., should

be avoided. This will reduce the chance of noise spikes entering the DC

power connection and affecting the unit.

2. The shield (screen) pigtail connection should be made as short as possible.

The connection point for the shield depends somewhat upon the

application. Listed below are the recommended methods of connecting the

shield, in order of their effectiveness.

a. Connect the shield only at the unit to earth ground (protective earth).

b. Connect the shield to earth ground at both ends of the cable, usually

when the noise source frequency is above 1 MHz.

c. Connect the shield to common of the unit and leave the other end of the

shield unconnected and insulated from earth ground.

3. Never run Signal cables in the same conduit or raceway with AC power

lines, conductors feeding motors, solenoids, SCR controls, and heaters,

etc. The cables should be run in metal conduit that is properly grounded.

This is especially useful in applications where cable runs are long and

portable two-way radios are used in close proximity or if the installation is

near a commercial radio transmitter.

4. Signal cables within an enclosure should be routed as far away as possible

from contactors, control relays, transformers, and other noisy components.

5. In extremely high EMI environments, the use of external EMI suppression

devices, such as ferrite suppression cores, is effective. Install them on

Signal cables as close to the unit as possible. Loop the cable through the

core several times or use multiple cores on each cable for additional

protection. Install line filters on the power input cable to the unit to

suppress power line interference. Install them near the power entry point

of the enclosure. The following EMI suppression devices (or equivalent)

are recommended:

Ferrite Suppression Cores for signal cables:

Fair-Rite # 0443167251 (RLC #FCOR0000)
TDK # ZCAT3035-1330A
Steward #28B2029-0A0

Line Filters for input power cables:

Schaffner # FN610-1/07 (RLC #LFIL0000)
Schaffner # FN670-1.8/07
Corcom #1VR3

Note: Reference manufacturer’s instructions when installing a line filter.

6. Long cable runs are more susceptible to EMI pickup than short cable runs.

Therefore, keep cable runs as short as possible.

INSTALLATION ENVIRONMENT

The unit should be installed in a location that does not exceed the
maximum operating temperature and provides good air circulation. Placing
the unit near devices that generate excessive heat should be avoided.

INSTALLATION

The power and 20 mA current loop connections should be made with 24
gauge, multi-conductor, shielded cable. Wire insulation should be stripped to
approximately 1/4 inch (stranded wires should be tinned with solder).
Accessing the terminal block and jumper is accomplished by removing the
four screws and nuts that hold the two case halves together. If the jumper
needs to be re-positioned, it should be done with NO power applied to the
module (module is shipped from factory in the 422 position). Connect the
power and 20 mA loop wires to the appropriate terminal block pins. The cable
is then routed through the groove at the rear of the module. Install the two
screws and saddle washers into the slots at the 25 pin D-connector. Position
the two case halves together, and secure with the four screws and nuts. Refer
to figure 1 below for assembly.

FIGURE 1