RLC-4 RS232 Level Converter in a DB9 backshell for the Wiligear^ WBD-500^

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 at: http://www.wiligear.com/?q=products/cpu-boards/wbd-500 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:

RLC-4	WBD500 J2
1 GND	4 GND
2 TX	3 Serial out
3 RX	2 Serial in
4 VCC	1 VCC
5 RTS	(no pin)
6 CTS	(no pin)

416049

User comments:

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."

Also:

• RLC-1 RS232 Level Converter in a DB9 backshell This is the base model of the RLC-4, just a different pin order.
• RLC-2 RS232 Level Converter in a DB9 backshell Exactly the same as an RLC-1, but with the pins setup for the ECS port on Sony Monitors.
• Would you be interested in a USB version of the RLC-4? Press or find out more about the RLC-3 USB to TTL serial converter
• RS-232 / I²C-Adapter & Parallel I/O Module

Shown With Backshell removed

RLC-4 Datasheet Digital Nemesis Pty Ltd www.digitalnemesis.com

Introduction

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.   Connections Logic Level Pin Assignments Pin Color Signal Description 4 BLK Gnd Ground Connection (0V). 3 YEL Data Out (TX) Data sent from the WBD-500 to the RS232 device. 2 RED Data In (RX) Data sent from the RS232 device to the WBD-500 1 WHT Vcc Power supply to the RLC-1. 3 to 5 Volts. x BLU RTS Request to Send signal sent from the RS232 device to indicate it wishes to transmit data. Not used in this version. x GRN CTS 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. RS232 Interface 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 attached circuit.   Specifications Symbol Parameter Conditions Value Unit Min Typ Max Isupply Vcc Power Supply Current No Load, TA = 25 Deg C   0.3 1 mA VIL Logic Level Input Threshold Low       0.8 V VIH Logic Level Input Threshold High   2     V VOL Logic Level Output Voltage Low Iout = 1.6mA (to Vcc)     0.4 V VOH Logic Level Output Voltage High Iout = 1mA (to Gnd) Vcc-0.6 Vcc-0.1   V DR Data Rate   300 400   Kbps Electrical Characteristics: 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. Symbol Parameter Value Unit Notes Vcc Unit Power Supply -0.3 to 6 V Relative to Ground VDout Input Voltage on Data Out Connection -0.3 to (Vcc +0.3) V Relative to Ground VDin Output Voltage on Data In Connection -0.3 to (Vcc +0.3) V Relative to Ground TStore Storage Temperature Range -55 to +125 °C     Options Available    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 sales@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 No 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 Interface

© Digital Nemesis Pty Ltd, 2001. Brisbane, Australia. www.digitalnemesis.com

Questions:

• 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.

See also:

• http://www.wiligear.com/?q=products/cpu-boards/wbd-500 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 device.
   
• http://www.awce.com/rs1.htm Kit 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.
   
• http://www.dontronics-shop.com/RLC-1-RS232-to-5-Volt-Level-converter-p-16186.html Another source for the RLC-1. As of 2008/02/05 the price is $26 USD. It may be a better option for people ordering outside the USA depending on the shipping.
   
• http://www.embedinc.com/products/ser 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.
   
• CoolMCU 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.
   
• http://www.ipenabled.com/ttl-rs232.html Almost $100 with power supply and shipping.
   
• http://www.superdroidrobots.com/shop/category.asp?catid=41 $10 more but has a longer cable. I personally would not think that a TTL signal would be reliable at higher speeds over a cable that long.