NEW FOREST ELECTRONICS

This device transparently converts RS-232 serial data to RS-485 or RS-422. It allows the creation of reliable long distance data communication systems using standard computer hardware.

RS-232 to RS-485/422 converter (non-isolated or isolated), mains powered plug top power supply (UK style 13A square pin version only), DB-25 to DB-9 adapter, instruction booklet, 12 months warranty, lifetime technical support by phone or email

• Bi-directional converter from RS-232 to RS-485/422 and vice versa (only data lines are converted, not control lines)
• RS-232 connection: provided by a DB-25 female connector, can be changed to DB-9 female by means of the adapter supplied. Switchable for RS-232 DTE or DCE operation
• RS-485/422 connection: provided by a 4-way terminal block (T+,T-, R+, R-) (both versions) and an RJ-11 connector (non-isolated version only) (Click here for view)
• Switchable for automatic RS-485/422 turnaround, i.e. automatic control of transmission or reception by means of RS-232 RTS control signal (see table below)
• Speeds: Up to 100 Kbps
• Suitable for point to point, multidrop, half/full duplex operation
• Monitor mode (non-isolated version only): the R+ and R- signal is fed to DB-25 pin 3, T+ and T- are changed to be R'+ and R'-, and are fed to DB-25 pin 2
• Isolated version: the RS-485/422 signals are electrically isolated (2000 V) from the RS-232 signals and power supply, for correct RS485/422 operation, and to help avoid ground loops etc.
• Power: DC 9V 200 mA (max.), suitable mains powered plug top PSU provided (230V UK style 13A square pin plug version only available)
• Housed in a rigid plastic case
• Weight: 60g (2.1 oz)
• Dimensions: (L x W x H): 75 x 54 18.5 mm ( 3.0 x 2.1 x 0.7 inches)
• CE marked, also meets class A of FCC part 15.

Further information on the switch settings:

Notes on SW1 settings:
1. "DCE" means the converter will act as an RS232 "Data Communications Equipment" (e.g. modem), so use this setting when connecting to a terminal (e.g. PC).
2. "DTE" means the converter will act as an RS232 "Data Terminal Equipment" (Transmit and Receive pins crossed over), so use this position when connecting to a modem. (This may need a DB-25 gender converter, because the converter is fitted with a female DB25 connector, as are most modems).
3. "Monitor" is a special mode available on the non-isolated version (IC-485S) only. As noted above, in this mode, the RS485/422 transmit terminals are switched to become a second pair of receive terminals, the signal from which is fed to the RS232 DB-25 pin 2, i.e. pin 2 acts as second receive pin (normally it is the transmit pin). (Note: RTS must remain low in this mode).

Notes on SW2 settings:
1. "TxOn, RxOn" means the RS485/422 transmit & receive functions are always on, e.g. used for point to point 4 wire full duplex.
2. "TxRTS, Rx(not RTS)" means the RS485/422 transmit function is on only when the RS232 RTS control signal is on (high), and the RS485/422 receive function is on only when RTS is off, e.g. used for point to point 2 wire half-duplex.
3.  "TxRTS, RxON" means the RS485/422 transmit function is on only when the RS232 control signal RTS in on, but the RS485/422 receive function is always on, e.g. used for multidrop 4 wire full duplex.

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                       © New Forest Electronics Tel. +44 (0) 1425 655559                 Issue 3.113    17 Oct 2024