At the U.S. Embassy in Vienna Saturday morning, President Carter will sit down for his first talks with President Leonid I. Brezhnev of the Soviet Union. Because of the circumstances of the meeting and the infirmities - political and physical, respectively - of the two leaders, this first American-Soviet summit conference in four years has generated limited expectations.

The list of what is not expected from the Vienna meetings is longer and more impressive than any recounting of the aims on either side, American officials are saying that no ground-breaking exchange is expected. Nevertheless, the governments and people of the two most powerful nations on earth will be watching the event with close attention, as will the great majority of the other nations of the world, which are affected by what the superpowers do.

No first meeting of two men with their fingers on the nuclear button can be all that modest in importance or implication. The almost godlike power of destructiveness in the hands of their two governments is the underlying reason for Soviet-American summitry and the central fact of Soviet-American relations. Indeed, the formal purpose of th Vienna meeting is to sign a painfully negotiated, meticulously detailed strategic arms limitation treaty (SALT II) placing agreed controls on the two nations' evergrowing nuclear weapons arsenals.

Carter, in a rambling after-dinner discourse to the nation's governors three months ago, said, "Thee most important single responsibility on my shoulders is to have peace and improved understanding, consultation, communication with the Soviet Union because on the superpowers' shoulders rest the responsibility for peace throughout the world."

Brezhnev touched the guts of the matter in earthier fashion in a Kremlin meeting last fall with Sen. Abraham Ribicoff (D-Conn.) and his Senate delegation. "Carter and I know we both have a couple dozen minutes when satellites will tell us missiles are coming" in case of war, he said. "There will be no more United States. But we will still get it in the neck."

Every president in this hair-trigger age of missiles and warheads has felt powerful urge to meet his opposite number. The result has been eight bilateral meetings in 20 years:

Dwight D. Eidenhower and Nikita S. Khrushchev at Camp David (1959).

John F. Kennedy and Khrushchev at Vienna (1961).

Lyndon B. Johnson and Alexsei N. Kosygin at Glassboro, N.J. (1967).

Richard Nixon and Brezhnev at Moscow (1972), Washington-San Clemente (1973) and Moscow 1974).

Gerald R. Ford and Brezhnev at Vladivostok (1974) and Helsinki (1975).

This week's Carter-Brezhnev summit according to American officials who have been preparing for it in great detail, will be different in several respects from any of the earlier meetings.

Due to the limitations imposed by Brezhnev's failing health, this is expected to be the most carefully prepared, almost choreographed, summit in history. The two sides have exchanged information in unusual detail about the topics for discussion and suggestions about the substance of the five business meetings between the two leaders.

There has been at least a tacit understanding for many weeks that there will be no surprises.The American side has been told by the doctors employed by U.S. interlligence that Brezhnev could have a seriously adverse reaction if confronted by surprise at the summit. The Soviet leader is expected to read most of his responses to Carter from a well-tabbed briefing book which has been prepared in the Krenlin, as he has in recent meetings with foreign leaders.

Carter has received a full intelligence briefing on Brezhnev. He has been told by foreign leaders who recently met Brezhnev, notably French Foreign Minister Jean Francois-Poncet who was at the White House Last week, that the Soviet leader is capable of several hours of concentration per day and that he departs occasionally from the briefing books to express his own ideas.

Carter's ability to speak with credible assurance about the long-term policy directions of his government is also questionable, for different reasons than those afflicting Brezhnev. Carter's popularity is at an all-time low in public opinion polls, his policies are under constant attack and threat of reversal in Congress, and his chances for success in the approaching presidential election year seem increasingly doubtful.

Early this week, on the very eve of the summit, the House of Representatives is threatening to overturn the implementing legislation for the Panama Canal Treaty, one of Carter's most important foreign policy intiatives and the Senate is expected to reject the Zimnbabwe-Rhodesia policy that was announced by the president only last Thursday.

An immediate shadow across the path of Brezhnev and Carter at Vienna will be that of the U.S. treaty ratification process. No matter how well the two men's talks might go, there is no real possibility of establishing a new stage in Soviet-American relations until the Senate has approved, or cast aside, the strategic bargain of seven years' negotiations.

The highest priority purpose for each side at Vienna will be to give a good sendoff to the SALT II treaty, which is to be signed in ceremonies on the last day of the meeting, Monday, June 18. The certain knowledge that their handiwork face a hard struggle for ratification is a constraint on all else that Carter and Brezhnev may do or say.

The fact that this week's meeting place is Vienna, much closer to Moscow than to Washington, is believed by some Soviet-watchers to reflect Brezhnev's reluctance to commit his full prestige to a SALT II treaty and to a course of Soviet-American relations that might be repudiated before the year is out. Carter publicly insisted it was the Russian leader's turn to come to the United States. The Soviet begged off for reasons theoretically related to Brezhnev's health, but that may be only part of their reason.

Carter is to leave Washington Thursday for Vienna. On Friday he and Brezhnev are to pay a joint formal call on their Austrian hosts and to attend the Vienna opera. Two business meetings each day are scheduled for Saturday and Sunday, two hours late in each morning and 90 minutes late in each day trailing into an informal dinner. Before the ceremonial signing on Monday, the two men are scheduled to have their only private meeting without advisers present.

The need for consective translation, which the Soviets prefer, will cut the talk in half. If Carter, and Brezhnev split the remaining time equally and their working sessions are not extended, each leader will have only 30 minutes in each morning business meeting and 22 minutes in each afternoon meeting to get his points across on a very big list of subjects of far-reaching international importance.

The agenda can be divided into four broad categories - SALT, other arms control issues, regional disputes and relationships, and bilateral U.S. Soviet relations. This is the main business and expected upshot in each area, as seen from Washington:

SALT - The treaty is to be signed and side assurances exchanged on such questions as the Soviet Backfire bomber. Carter's aides are unwilling to say that he has given up his idea of negotiating some last-minute SALT II reductions at the summit, but it is considered quite unlikely.

SALT III negotiations are to begin immediately after the ratification of SALT II. The principles and problems of deeper cuts and stronger limitations in th next round are to be discussed.

Cooperative measures to improve vertification are to be part of SALT III, by mutual agreement. Any such measures set in motion or approved now could enhance the chances for ratification of SALT II.

Carter may bring up the U.S. plan to monitor some aspects of Soviet missile lauches with overflights of Turkey by U2 reconnaissance planes. Turkey has said it will permit the over flights only if the Soviets do not object.

Other arms control - Despite earlier hopes, there is little expectation of a breakthrough or preliminary agreement ready to be announced in any field.

The brightest hope, a first-step testing ban on killer satellites in space, proved too complex for quick agreement.

The United States is unwilling to accept a Soviet proposal for quick bilateral cuts in troops, tanks and nuclear weapons in central Europe without resolving a dispute on the size overall forces.

The United States hopes to go back to bargaining on superpower curbs on conventiaonal arms sales to Third World regions, after a six-months freeze in the talks due to U.S. decisions. Washington is ready to reopen informal talks with Moscow about demilitarization of the Indian Ocean, after more than a year's U.S. imposed hiatus.

In these areas and the comprehensive ban on nulear tests, currently held up by British reluctance, Carter and Brezhnev are likely to report some progress and pledge future efforts, in come cases announcing new negotiations. They will also issue a strong statement of concern about the spread of nuclear weapons to other nations.

Regional disputes - The United States will appeal for Soviet restraint in the Middle East and Africa despite the cross purposes of the two nations in many areas. Soviet acquiescence in some kind of United Nations force to police the Egyptians-Israeli pullback in the Sinai will be solicited.

Soviet arms to Cuba and Soviet sponsorship of Cuban troops in Africa are likely to be discussed.

China is expected to be at the top of Brezhnev's regional concerns, whatever the formal listing. Carter will want to talk about Soviet backing for Vietnam and possibility about Korea.

Bilateral relations - The centerpiece for public display is expected to be talk of better communications, possibly including annual Soviet-American summit conferences.

Carter is seeking a way to extend "most favored nation" trade benefits to the Russians, despite their unwillingness to give explicit assurances about emigration policies as required by the Jackson-Vanik amendment. In view of the recent increase in emigration of Soviet Jews and possible future releases of dissidents, implicit assurances may be worked out at Vienna.

None of this, even the signing of a completed but embattled treaty, is the stuff of stirring promises, sweeping declarations or an emerging turn in human history. Like the lengthy lawyer's and technician's document which is SALT II, this is the cautious fine print of superpower relations rather than the big type.

It might have been different if the two men had met near the outset of Carter's term, as he wished at the time. But even before the 1976 election, Brezhnev told former Ambassador W. Averall Harriman, Carter's adviser, that a meeting should await the completion of SALT II, which then appeared to be just over the horizon. Brezhnev said he did not want an inconclusive summit.

During the tortuous arms negotiations, the Carter-Brezhnev dialogue was limited to public declarations, a mostly sterile private correspondence, the use of the Washington-Moscow telegraphic "hot line" on one or two occasions, and messages through foreign ministers, aides and intermediaries.

Carter often expressed frustration at Soviet conduct and told close advisers he wished he could "get my hands on Brezhnev" toset thing right. Whatever the chances of this at any time, changing circumstances have diminished the possibility now. While both men are at the helm of their parties and governments, the struggle for succession is under way both in Washington and Moscow. The competition in Washington is open; in Moscow it is secret.

Among the few imponderables about the highly programmed meeting is the personal chemistry of the two principals. One of Carter's more erudite advisers, a former professor, wondered if even this is hostage to fate. He kept recalling a passage from Leo Tolstoy's classic novel, "War and Peace," about the battle of Borodino, Napoleon's last great "victory" on the approach to Moscow in 1812.

In historical events great men are but labels rather than causal forces, Tolstoy wrote. "Every action of theirs, that seems to them an act of their own free will is in historical sense not free at all, but in bondage to the whole course of previous history, and predestined from all eternity." CAPTION: Picture, Hofburg will be site for ceremonial Viennese signing of strategic arms limitation treaty. The Christian Science Monitor