RLC-4 RS232 Level Converter in a DB9 backshell for
The RLC-4 is a version of our RLC-1 TTL to RS232 converter with the pins
already setup for the Wiligear WBD-500 Integrated Radio Board (check it out
it's a tiny but powerful, 500mW (27dBm) integrated radio platform offering
seamless wireless performance on the 2.4 GHz spectrum )
The RLC-4 plugs right into the J2 connector on the WBD-500 to connect the
unit to your PC or other RS232 host equpment. Because the RTS and CTS pins
are not used, the connector goes on with pin 1 of the RLC unit on pin 4 of
J2 and is oriented so that pins 5 and 6 hand off in the air:
3 Serial out
2 Serial in
Brady Palmquist says: "James...got your RS232/TTL cable today. FAST! And
it looks great. Will work great for programming radios. Thanks VERY much."
Bill Speary says: "... The board works perfectly with your cable.. Thanx
for your info."
The RLC-1 RS232 to 3-Volt or 5-Volt (CMOS/TTL) Level converter provides
a simple, low-cost and easy to use solution to interfacing a CMOS or TTL
based circuit to an RS232/EIA232 serial port.
The RLC-1 contains an internal circuit to provide the positive and negative
voltages needed for true RS232/EIA232 compatibility and to convert these
voltages back to logic levels.
It is particularly suited to micro-controller applications; for instance
the PIC or ATMEL families of devices and products using these.
The RLC-1 is built into a small DB9 backshell with a short (10cm or 4") lead
terminating in a standard 0.1" (2.54mm) Molex KK-series 6 pin connector.
The connector is used to provide power to the converter and deliver the Serial
data signals to the attached circuit.
Its small size and convenience make it ideal for prototype or one-off systems,
eliminating the need to design and debug extra level shifting circuits. It
is also useful for circuits that need periodic connection to a host like
dataloggers where a single converter can be used with many products, reducing
the parts count and therefore cost for the individual units.
Logic Level Pin Assignments
Ground Connection (0V).
Data Out (TX)
Data sent from the WBD-500 to the RS232 device.
Data In (RX)
Data sent from the RS232 device to the WBD-500
Power supply to the RLC-1. 3 to 5 Volts.
Request to Send signal sent from the RS232 device to indicate
it wishes to transmit data. Not used in this version.
Clear to Send signal sent to the RS232 device indicating
that it can begin sending data. Not used in this version.
Logic Level Interface
The logic level (CMOS and TTL compatible) interface is a Molex KK Series,
locking and polarised 6 pin crimp terminal housing. For the RLC-4 the last
two holes are not used.
Note that the logic level interface is not isolated from the RS232 level
interface and they share a common Ground.
The RLC-1 is build into a DB9 Backshell and comes with a female DB9 connector.
The DB9 RS232 connector is wire as a standard "Null Modem"; DTR, DSR and
CD are permanently wired together but the RTS and CTS signals are provided
to the 5-Volt interface and must be connected together if not used in the
Vcc Power Supply Current
No Load, TA = 25 Deg C
Logic Level Input Threshold Low
Logic Level Input Threshold High
Logic Level Output Voltage Low
Iout = 1.6mA (to Vcc)
Logic Level Output Voltage High
Iout = 1mA (to Gnd)
Vcc = 5V +/-10%, TA = -40 to 85 Deg C, unless otherwise
specified. Typical Values are referred to TA = 25 Deg C.
Absolute Maximum Ratings:
Absolute Maximum Ratings are those values beyond which damage to the device
may occur. Functional operation under these conditions is not to be implied.
Unit Power Supply
-0.3 to 6
Relative to Ground
Input Voltage on Data Out Connection
-0.3 to (Vcc +0.3)
Relative to Ground
Output Voltage on Data In Connection
-0.3 to (Vcc +0.3)
Relative to Ground
Storage Temperature Range
-55 to +125
Digital Nemesis Pty Ltd makes a single standard unit, but is able to
adapt them as needed. Note that a minimum order quantity will apply for
non-standard configurations. For more information, please contact
salesSTOPspam at digitalnemesis.com.
The following are some of the available options: (all units now support 3
Volt as well as 5 Volt operation)
Rugged All Metal Backshell
Bare Leads for Logic Level Interface
Custom Connector for Logic Level Interface
RTS and CTS internally connected and a 4 Pin connector for the Logic Level
Arthur asks: "Does the RLC invert the Pin-3 data out signal?" James Newton
answers: "Yes, the signal is inverted in terms of electrical polarity.
e.g. a TTL low will generate a positive voltage on the TX output pin, a TTL
high will generate a negative TX. But the other possible correct answer is
No, the signal is not inverted in terms of logic. In the
RS232 standard, a low electrical level
(3 to 15 volts) is defined as a logic 1, or 'on' or 'high'
and is referred to as 'marking.' So a TTL high which is a positive voltage,
will generate an RS232 "high" which is a negative voltage.
The WBD-500 is a tiny but powerful, 500mW (27dBm) integrated radio platform
offering seamless wireless performance on the 2.4 GHz spectrum. The RLC-4
is designed to connect between the WBD-500 and a PC or other RS232 level
with larger components. Does not include a cable. 5 Volt operation only.
As of 2006/08/03 the cost was $10 for the PCB only, $14 for the kit and $26
A&T. If you don't mind the size and want to save $5 in return for building
the kit, this is a good option.
Larger, no case, no cable, does not convert RTS or DTS, does not support
3.3v. Ss of 2008/02/05 the price is one dollar less up to qty 4, but the
5 unit price is $13.80 which is quite good.
Converter Cable. Physically larger than the RLC-1. Used to sell
a version that was not a true MAX232, but the current version seems like
a good product. From Canada, so expect shipping and customs delays. Priced
at $16 plus $11 express shipping to US (5 to 7 business days advertised)
for a total price of $27. Compare with our $21 + $6 for 2-4 day Priority
Mail shipping. The price is the same, the shipping is faster. Read the ebay
comments: Many times shipping is fast, but you may be the one that gets held
up in customs. "Product works great, but it took over three weeks for me
to receive it (USA)." kielziz( 5 ) Jun-01-06 08:21 "Works as
described. Shipping is a little slow." asylumboy( 4 ) Jun-01-06 08:10 and
so on. In the end, the same thing costs less in Canada, but more to ship
to the USA. I have offered to resell this product in the USA, but he is
apparently not interested.