All About Cables

Gauge and RS232 cables are often very confusing to many users. There are often multiple ways to connect a gauge or serial device to an interface or a computer. 

Digital Gauges
These gauges consist of calipers, micrometers, digital indicators, etc., and are available from companies such as Mitutoyo, Federal, Ono Sokki, CDI, Fowler, Starrett, Brown & Sharpe, etc. These gauges do not have an RS232 output and it is not uncommon for a gauge from one manufacturer to be private labeled by another company. For example, the CDI digital indicator is also sold under the Starrett name.

There are 4 basic output formats used for digital gauges. These output formats are typically referred to as Mitutoyo, Federal, CDI and Ono Sokki. It is not uncommon for a gauge manufacturer to offer digital gauges that have several different gauge output formats. Some gauges, such as the CDI digital indicators, support multiple gauge output formats.

Cables for the Mitutoyo brand of gauges are manufactured by Mitutoyo and are available from many Mitutoyo dealers.

RS232 Gauges that Use Custom Cables From the Gauge Manufacturer
Gauges from manufacturers such as Fowler/Sylvac, Starrett, Mahr/Federal, etc. normally require cables produced by the gauge manufacturer. These cables typically have custom molded connectors on the gauge end and a 9-pin D-sub female connector on the other end.

Many Starrett gauges generate an RS232-type output signal; however, the voltage and logic levels of these signals (referred to as TTL level signals) are inverted from the typical RS232 devices. The basic cables from Starrett have a 6-pin connector and cannot be connected to standard RS232 serial ports without additional signal conditioning or adapters. 

RS232 Gauges and Devices that Use Standard DB9 Extension Cables
The standard serial port on a PC has a 9-pin D-sub male connector. Most serial devices, such as scales, barcode readers, torques testers, etc., use a 9-pin female D-sub connector for their RS232 output. These devices can use a standard straight through serial extension cable and can be plugged directly into the DataGet RS232 adapters.

RS232 Gauges and Devices that Require Custom Cables
Some device manufacturers provide non-standard connections for their serial output. The standard PC serial port uses a 9-pin D-sub male connector. D-sub connectors also come in 15, 25, 37 and 50 pin versions. Other types of commercially available connectors may also be used instead of the common D-sub connectors.  Cables for these devices will need to be either custom-made or supplied by the gauge manufacturer.