StarTech.com IC485S User manual

Installation Manual
IC485S
IC485SGB
IC485SEU
Interface Converter
RS-232 to RS-485/422 Serial Interface Converter

110
Overview
Changing line signals is no longer a problem. StarTech.com’s IC485S / GB / EU
converts RS-232 serial interfaces to RS-485/422 serial interfaces. This 2 in 1 converter
converts RS232C to either the RS 485 or RS 422 interface. Other features include DCE/
DTE selectable modes, point to point multidrop configuration and the ability to monitor
RS 485/422 signals.
The IC485S / GB / EU can be powered from the following two ways:
1. DC 9V, 200mA power adapter
2. The pin #9 of the RS-232 connector
The following is a figure of the IC485S / GB / EU:
Features
• Two in one converter-Converts RS232C to either RS-485 or RS-422
• DCE/DTE mode selectable
• Supports point to point multidrop configuration
• Can be used to monitor RS-485/422 signals
• Full or half duplex operation
Specifications
Data rate
RS-232 connector
RS-485 connector
Dimensions (mm)
Power
Up to 1MB/sec
Cable length Up to 4000ft.
DB25 Female
RJ11 Female or 4 terminal block
54 x 74 x 19
Self-powered or DC 9V 200mA
Radio and TV Interference
Warning!!! This equipment generates, uses and radiates radio frequency energy and if
not installed and used in accordance with the instruction manual may case interference
to radio and television reception. It has been tested and found to comply with the limits
for a Class A computing device in accordance with the specifications in Subpart J of
Part 15 of FCC Rules, which are designed to provide reasonable protection against
such interference when operated in a commercial environment. Operation of this
equipment in a residential area is likely to cause interference, in which case the user at
his own expense will be required to take whatever measures may be required to
correct the interference.
If this equipment does cause interference to radio or television reception, which can be
determined by turning the equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following measures:
1. Reorient the receiving antenna.
2. Relocate the computer with respect to the receiver.
3. Move the computer away from the receiver.
4. Plug the computer into a different outlet so that the computer and receiver are on
different branch circuits.
5. Ensure that the mounting screws, attachment connector screws and ground wires
are tightly secured.
6. Ensure that good quality, shielded and grounded cables are used for
data communications.
If necessary, the user should consult the dealer or an experienced radio/television
technician for additional suggestions.

92
Getting Started
This section is designed to help you prepare the IC485S / GB / EU for installation.
Please read through this section carefully before attempting to install the converter.
Unpacking the IC485S / GB / EU
This package should contain:
• 1 x interface converter
• 1 x power adapter
Installation
Before installing the IC485S / GB / EU you will need a 4-wire cable. This cable must go
from your location to the place you want to connect to.
1. Decide on one of the 6 possible configurations suitable for your application. Check the
Operation for the correct slide switch settings and phone wires connection, then
connect the IC485S / GB / EU to the PC.
2. Turn on the PCs.
3. Insert the adapter’s plug into the power jack on the right side of the converter.
4. Plug the power adapter into an AC outlet. The unit is not ready for operation.
Switch Function Description
Device Mode Selection
Position 1: DCE means that the IC485S / GB / EU is set to the DCE mode and must be
connected to a DTE device.
Position 2: DTE means that the IC485S / GB / EU is set to the DTE mode and it must be
connected to a DCE device.
Position 3: Monitor means that the IC485S / GB / EU is set to the monitor mode and it is
used to monitor the RS-485 line signals.
Transmitting and Receiving Mode Selection
Position 1: (TxON, RxON) means the IC485S / GB / EU is always in transmitting mode
and in receiving mode (using in Point-to-Point mode).
Position 2: (TxRTS, RxRTS) means the IC485S / GB / EU is in transmitting mode while
the RTS is at a high level and it is on receiving mode while the RTS signal is at a low
level (using in Multidrop mode).
Position 3: (TxRTS, RxON) means the IC485 / GB / EU is always in receiving mode and
it is in transmitting mode only while the RTS signal is at a high level (using in Multidrop
mode to monitor the RS/485 line signal).
Note: DTE means Data Terminal Equipment. DCE means Data Communication
Equipment. For more detailed information, refer to the Appendix.
Appendix
Troubleshooting
If failure of printing still exists upon the above solutions, please contact your dealer
for help.
RS-232 DCE/DTE Description
Note: The DTE mode devices must be connected ti a DCE mode device because the
polarity of the communication signals are different. The shadow area is a connection
example for a DTE device to a DCE device.
Problem Solution
Failure of Data Transmission 1. Check that the DC9V power adapter
is available.
2. Check that the IC485SEU is plugged
securely to the PC.
3. Check that the 4-wire cable is
connected properly at both ends.
4. Check that the SW1 and SW2 are
properly set.
Data Loss or Error Check that the data rate and data format
are the same for both devices.
Device's Connector Pin # Cables IC485S/GB/EU
DCE
DB9
DTE
DB9
DCE
DB25
DTE
DB25
25/25 or
9/25-Pin
DCE
DB25
DTE
DB25
2 3 3 2 Tx Rx 3 2
3 2 2 3 Rx Tx 2 3
8 7 5 4 RTS CTS 5 4
7 8 4 5 CTS RTS 4 5
5 5 7 7 GND GND 7 7

38
Operation
The IC485S / GB / EU supports 4 kinds of functions in 6 types of configurations.
Point-to-Point
Point-to-Point configuration means two devices that locate different places can be linked
together to communicate through a couple of IC485S / GB / EU devices.
If the PC1 is a DTE device, then the Device A SW1 should be set to DCE. If the PC1 is a
DCE device, the the Device A SW1 should be set to DTE. The switch setting method for
the Device be is identical to Device A’s.
Others
Terminal Block Definition
The four-screw terminal block has different definitions in different operation modes.
In the DCE/DTE mode, the terminal #1 (-V) and #2 (+V) are configured to transmit data,
the transmitter; the terminal #3 (+V) and #4 (-V) are configured to receive data,
the receiver,
In the monitor mode, the terminals #1 and #2 are respectively the positive and negative
of receiver #1; the terminal #3 and #4 are the positive and negative of receiver #2.
Self Test
To test the internal circuit of the interface converter, connect a loop-back terminal to the
unit and process as follows:
1. Set SW1 to DCE (if the loop-back terminal is a DTE configuration).
2. Set SW2 to TxON, RxON.
3. Connect one wire from Tx-(#1) to Rx-(#4), and connect another wire from Tx+(#2)
to Rx+(#3).
4. Set the terminal to full duplex and enter data then the data should be displayed on
the screen.
5. If this occurs, the internal circuit is operational.
PC1
COM1/
COM2
T+
T-
R-
R+
IC485S
=>
A
PC2
COM1/
COM2
R+
R-
T-
T+
IC485S
=>
B
Device
A
B
SW1
DCE/DTE
DCE/DTE
SW2
TxON, RxON
TxON, RxON
Point-to-Point/4-Wire
Full Duplex
Configuration
PC1
COM1/
COM2
T+
T-
R-
R+
IC485S
=>
A
PC2
COM1/
COM2
R+
R-
T-
T+
IC485S
=>
B
Device
A
B
SW1
DCE/DTE
DCE/DTE
SW2
TxRTS, RxRTS
TxRTS, RxRTS
Point-to-Point/2-Wire
Half Duplex
Configuration
Pin #1 DCE/DTE Monitor
1 Transmitter - V Receiver #1 - V
2 Transmitter + V Receiver #1 + V
3 Receiver + V Receiver #2 + V
4 Receiver - V Receiver #2 - V

74
Multidrop
Multidrop configuration means that more than two devices can be linked all together to
communicate to one another through many IC485S / GB / EU devices. In this
configuration, one of the IC485S / GB / EU devices will be connected to a master device
and the rest of the IC485S / GB / EU devices will be connected to many other slave
devices.
Note: Bn means any one of the B1, B2, B3 and so on.
Monitor Mode
Monitor configuration means an IC485S / GB / EU device can be wired to the lines of
RS-232 or RS-422 devices to monitor the line signals. In this configuration the IC485S /
GB / EU will change the function of the T+ and T- to R’+ and R’- respectively.
Before operating, the user must complete the installation according to the
procedure mentioned.
Once the installation has been done, the device should operate as the setting function.
Note: R+ and R- signals are converted and linked to the RS-232 port and DB25 pin 3.
R’+ and R’- (T+ and T-) signals are converted and linked to the RS-232 port DB25 pin 2.
Note: The RTS must be at the low level in monitoring mode.
PC1
COM1/
COM2
T+
T-
R-
R+
IC485S
=>
A
PC2
COM1/
COM2
R+
R-
T-
T+
IC485S
=>
PC3
COM1/
COM2
=>
PC4
COM1/
COM2
=>
B1
R+
R-
T-
T+
IC485S
B2
R+
R-
T-
T+
IC485S
B3
Device
A
B
SW1
DCE/DTE
DCE/DTE
SW2
TxON, RxON
TxRTS, RxON
T+
T-
R-
R+
Device 1
R+
R-
T-
T+
PC
COM1/
COM2
=>
Device 2
T+ (R'+)
T- (R'-)
R-
R+
IC485S
A
Device
A
SW1
MONI
SW2
TxRTS, RxON
Multidrop/4-Wire
Full Duplex
Configuration
Monitoring
Configuration

56
Simplex/Transmit, Receive Only
Simplex configuration means that more than two devices can be linked all together to
communicate through many IC485S / GB / EU devices. Its configuration is like the
Multidrop’s, but the master device can talk only and the slave devices can listen only.
Note: Bn means any one of the B1, B2, B3 and so on.
PC1
COM1/
COM2
T+
T-
R-
R+
IC485S
=>
A
PC2
COM1/
COM2
R+
R-
T-
T+
IC485S
=>
PC3
COM1/
COM2
=>
PC4
COM1/
COM2
=>
B1
R+
R-
T-
T+
IC485S
B2
R+
R-
T-
T+
IC485S
B3
Device
A
B
SW1
DCE/DTE
DCE/DTE
SW2
TxRTS, RxRTS
TxRTS, RxRTS
PC1
COM1/
COM2
T+
T-
R-
R+
IC485S
=>
A
PC2
COM1/
COM2
R+
R-
T-
T+
IC485S
=>
PC3
COM1/
COM2
=>
PC4
COM1/
COM2
=>
B1
R+
R-
T-
T+
IC485S
B2
R+
R-
T-
T+
IC485S
B3
Device
A
B
SW1
DCE/DTE
DCE/DTE
SW2
TxON, RxON
TxON, RxON
Multidrop/2-Wire
Half Duplex
Configuration
Simplex/Transmit,
Receive Only
Configuration