local sec_codes = {'SU26219RMFS4', ...}

 -- infinite loop to compensate for problems with getting the price
        while true do

         for _, sec_code in ipairs(sec_codes) do

            quoteLevel = getQuoteLevel2('TQOB', sec_code)
            if quoteLevel.offer then
                pc = tonumber(quoteLevel.offer[1].price)
            end
            if pc == 0 or pc < 0 or pc == nil then
                co.toLog(sn, '    still nothing...')
                sleep(math.random(1000, 2000))
            else
                break
            end
         end
        end

co = require('m_common_objects')
to = require('m_trading_objects')
sn = 'example_9.lua'

function OnInit()
    is_running = true
    co.toLogInit(sn, 'session begins.')
end

function OnStop()
    is_running = false
    co.toLogStop(sn, 'session ends.')
end

function main()

    local pc = 0
    local trans_id_buy = 0
    local trans_id_sell = 0
    local price_pc_buy = 0

    local sec_code = ''      -- instrument name
    local price_margin

    --while to.is_running do
        local quoteLevel
        local pc = 0
        sec_code = 'SU26219RMFS4'

        -- infinite loop to compensate for problems with getting the price
        while true do
            quoteLevel = getQuoteLevel2('TQOB', sec_code)
            if quoteLevel.offer then
                pc = tonumber(quoteLevel.offer[1].price)
            end
            if pc == 0 or pc < 0 or pc == nil then
                co.toLog(sn, '    still nothing...')
                sleep(math.random(1000, 2000))
            else
                break
            end
        end
        co.toLog(sn, 'pc = '..pc)


        price_margin = 0.25

        -- get transaction IDs
        trans_id_sell, trans_id_buy = to.getTransID(sn)

        -- submit Buy order
        price_pc_buy = to.pbuy(pc, price_margin)
        co.toLog(sn, 'price_pc_buy = '..price_pc_buy)
        to.send_order_buy(sn, trans_id_buy, sec_code, price_pc_buy, 1)
    --end

    co.toLogMain(sn, 'main function ends.')
end

local function send_order_buy(sn, tid, sc, pb, qt)
    -- sn  - script name
    -- tid - transaction ID
    -- sc  - security code (instrument name)
    -- pb  - price buy
    -- qt  - quantity
    local order = {}
    local err = ''

    co.dbg(sn, tid)
    while true do
        order = {
            ['ACCOUNT'] = trading_objects.ACCOUNT,
            ['CLIENT_CODE'] = trading_objects.CLIENT_CODE,
            ['CLASSCODE'] = trading_objects.CLASS_CODE,
            --
            ['ACTION'] = 'NEW_ORDER',
            ['EXECUTION_CONDITION'] = 'PUT_IN_QUEUE',
            ['TRANS_ID'] = tid,
            ['SECCODE'] = sc,
            ['OPERATION'] = 'B',
            ['PRICE'] = tostring(pb),
            ['QUANTITY'] = tostring(qt)
        }

        err = sendTransaction(order)
        co.dbg(sn, err)

        if err ~= '' then
            co.toLog(sn, 'Error! '..err)
        else
            break
        end
        sleep(math.random(1, 100))
    end
    co.toLog(sn, sc..'; tid='..tid..'; B ; price='..tostring(pb)..'; qty='..tostring(qt))
    return tid
end