I am often asked about the differences in the various systems that ESI has made over the years, and what phones are compatible with which control units and which circuit cards go with which systems.

Here is some history of the ESI product line which may give you some good information. From the late 80’s to the early 90’s ESI came out with the voiceworks which was a standalone voice mail system which interfaced with many phone systems such as Atlas, Comdial and At+t.

The next system to come out was the IVX classic in the mid 90’s.

This system used the 16 button phone with 3 park keys and a 4×8 circuit card for expansion. The phones and cards are only usable on the IVX classic systems.

A few years later the ivx 128 came out. This was an expandable system that could go to 42 lines and 84 phones. The DP1 16 button phone with 1 park key was used on this system and can also be used on later system circuit cards which include the 612, 684 and D12 were available and able to be used on the later E class gen 1 and x class systems.

After the 128 came the 20 and 20 plus telephone systems which used the same phones as the ivx 128. A few years later came the E class and the S class systems gen 1 and gen 2.

The E class gen 1 was capable of going to 24 lines and 48 phones.

It used the same cards as the ivx 128 but was able to use the new 48 key hdfp telephones which were larger than the 16 button and had 30 programmable keys.

Shortly after came the s class gen 1 which used the 48 key or the smaller 24 key which had 12 programmable keys.

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The s class gen 1 used a 4x8x2 expansion card which was only able to be used on the gen 1 S class The gen 1 S class was also called the 42 s and could expand to 12 lines and 24 phones.

The next systems to come down the pike were the generation 2 systems.

The S class gen 2 also called the 56 s could expand to 16 lines and 32 phones and used the 482 gen 2 expansion cards which could also be used in the later c+ and cs 50 systems.

The E class generation 2 or 72E took the new E2 cards( 612,684 and D12) but could also use the older Ivx cards. The E2 cards could support the ESI cordless and were able to be used in the communication servers which came later.

There was also the X class which came in a rack mountable cabinet which could expand to take 14 cards which could be ivx or E2 and mounted on a card carrier so they could be plugged into the ksu.

After this series of systems came the communications servers which arrived around 2008. The CS 50 could go to 16 lines and 32 phones and could use the S class gen 2 expansion cards or the newer 482 cards. The next size up was the CS 100 which takes only E2 circuit cards such as the E2 612,E2 684 and E2 D12.

The ESI CS 200 was the next larger system and had the same configuration as the X class but could only take the E2 cards on a CS card adapter or the new CS cards such as the CS 612,CS 684 and CS d12 circuit packs.

The newest versions of software higher than xx.05.52 can take the newer 60D phone and the 40D telephone.

I hope this blog has been a help to you.

If you have any more questions you can always call me, at 1-888-689-1711

Pete