HSSI (High-Speed Serial Interface) to V.35, X.21, RS422, RS530

2040 MC-MT/48	V.35 DCE TO HSSI DTE CNVRTR
2040 MC-MT/UI	V.35 DCE TO HSSI DTE CNVRTR
2040 MT-MC/48	HSSI DCE TO V.35 DTE CNVRTR
2040 MT-MC/UI	HSSI DCE TO V.35 DTE CNVRTR
2041 FC-MT/UI	X.21 TO HSSI CONVERTER
2041 FT-MC/UI	X.21 TO HSSI CONVERTER
2042 MC-MT/UI	RS422 HSSI CONVERTER
2042 MT-MC/48	2042 MT-MC/48
2042 MT-MC/UI	RS422 TO HSSI CONVERTER

a 2040 can convert HSSI to V.35 or RS422 or RS232 X.25

note DCE and DTE pin out on interfaces

Is Your Interface a DTE or a DCE?

One of the stickiest areas of confusion in datacom is over the terms "transmit" and "receive" as they pertain to DTE (data terminal equipment) and DCE (data communication equipment). In synchronous communication, this confusion is particularly acute, because more signals are involved. So why is it that you sometimes send data on TD, and other times you send data on RD? Is this just a cruel form of mental torture? Not really. The secret lies in adopting the proper perspective. In data-com, the proper perspective is always from the point of view of the DTE. When you sit at a PC, terminal or workstation (DTE) and transmit data to somewhere far away, you naturally do so on the TD (transmit data) line. When your modem or CSU/DSU (DCE) receives this incoming data, it receives the data on the TD line as well. Why? Because the only perspective that counts in data-com is the perspective of the DTE. It does not matter that the DCE thinks it is receiving data; the line is still called "TD". Conversely, when the modem or CSU/DSU receives data from the outside world and sends it to the DTE, it sends it on the RD line. Why? Because from the perspective of the DTE, the data is being received! So when wondering, "Is this line TD or RD? Is it TC or RC?" Ask yourself, "What would the DTE say?"

HSSI (High-Speed Serial Interface) devices can now bi-directionally communicate with V35 devices at speeds up to 10 Mbps. The V35- HSSI Interface Converter supports all HSSI co-directional timing patterns, two loopback modes (local line and remote line), plus data and control signals.

Two versions of the Interface Converter are available. The 2040MT/MC lets a V.35 DTE device communicate with a HSSI DCE device. The 2040MC/MT lets a V.35 DCE device communicate with a HSSI DTE device. Both versions are equipped with a male M/34 connector on the converter end, and a male HD-50 on the end of a 6 foot (1.8m) cable (other connector genders and cable lengths are available on a custom basis). Power is supplied to the Model 2040 by an external AC transformer

Communications V.35 DCE device to HSSI DTE data device.	M/34 DTE/HD50 DCE (Male M/34 to male HD50)	2040MT-MC/UI
Communications HSSI DCE device to V.35 DTE data device.	M/34 DCE to HD50 DTE (Male M/34 to male HD50)	2040MC-MT/UI