====== Omron SYSMAC CS/CJ/CP Series & NCJ series C-Command protocol ======

C-mode (Host Link) commands form a command/response system for serial communications (Host Link Mode) to perform various control operations between a CPU Unit and a host computer directly connected to it. These
operations include reading from and writing to I/O memory, changing operating modes, executing forced set and forced reset operations, and so on.

In WebHMI, this protocol is implemented using custom protocol. See the sample below.

To create a protocol follow the link below:
{{ :conn:conn-examples:link-to-custom-protocol-new.png?direct&800 |}}

and add a new protocol:
{{ :conn:conn-examples:add-custom-protocol-button.png?direct&800 |}}

{{ :conn:conn-examples:omron_-_custom-protocol-settings.png?direct&800 |}}

<code lua>
--[[ OMRON HOSTLINK PROTOCOL SUPPORTING 
		THE FOLLOWING C-COMMANDS FOR SYSMAC CS/CJ/CP Series & NCJ 
		
        4-3-2 CIO AREA READ WRITE (ref. to w342 reference manual)
        4-3-4 HR AREA READ WRITE
        4-3-7 DM AREA READ WRITE
--]] 

STX = '@'
CR = 0x0D
FRAME_TAIL = '*' .. string.char(CR)

-- symbols positions 
STX_POS = 1 
NODE_ID_POS = 2 
HEADER_CODE_POS = 4  
END_CODE_POS = 6 
NORMAL_END_CODE = 0 
WORD_DATA_START_POS = 8 
WORD_DATA_FCS_POS    = WORD_DATA_START_POS + 4
DWORD_DATA_FCS_POS   = WORD_DATA_FCS_POS + 4 * 1 -- x by word count 
WR_CMD_PAYLOAD_END = 7 

function createDevices ()
   addDevice{name = "CIO",  shift = 0, base = 10, xtraFields = {}}
   addDevice{name = "HR",   shift = 0, base = 10, xtraFields = {}}
   addDevice{name = "DM",   shift = 0, base = 10, xtraFields = {}}
end
-- commands 
READ_COMMANDS   = {CIO = "RR", HR = "RH", DM = "RD"}
WRITE_COMMANDS  = {CIO = "WR", HR = "WH", DM = "WD"}

-- field lengthes 
NODE_ADDR_LEN, MEM_ADDR_LEN = 2, 4 

DEC_BASE, HEX_BASE = 10, 16 

-- dataType –  0 = Bit, 1 = Byte, 2 = Word, 3 = Double Word, 4 = UnixTime
REG_STRUC_BIT_TYPE = 0 
REG_STRUC_WORD_TYPE = 2 
REG_STRUC_DW_TYPE  = 3 -- will read 2 words for these types 
REG_STRUC_UT_TYPE  = 4  

DATA_FORMAT_DICT = {[0] = "REG_STRUC_BIT_TYPE",[2] = "REG_STRUC_WORD_TYPE",  
                    [3] = "REG_STRUC_DW_TYPE", [4] = "REG_STRUC_UT_TYPE"}

readCache = {
    CIO = { unsorted = {}, sorted = {} }, -- grouped ranges will be here 
    HR =  { unsorted = {}, sorted = {} }, -- cached data will be here 
    DM =  { unsorted = {}, sorted = {} }
}

VERY_FIRST_SCAN = 1 
SECOND_SCAN = 2 
scanCounter = VERY_FIRST_SCAN 
singleRegReadCounter = 0 -- to count single reads 

function onScanStart()
    
    if (singleRegReadCounter ~= 0) then 
        DEBUG("Made " .. singleRegReadCounter .. " single reads on previos scan!")
        singleRegReadCounter = 0 
    end 
    
    printOnceFlag = false 
    
    -- MAKE GROUP READ LISTS -------------------------------------    
    if (scanCounter == SECOND_SCAN) then 
        DEBUG("Second scan!")
        for devName, deviceData in pairs(readCache) do 
            deviceData.sorted = getSortedTableKeys(deviceData.unsorted)  
            -- tprint(deviceData.sorted)
            -- now grouped 
            local groupsFound = getRangesFromTab(deviceData.sorted) ; -- DEBUG("Making grouped ranges for " .. devName)
            if groupsFound then 
                deviceData['group'] = groupsFound
                deviceData['stored'] = {}  -- create a key for cached data 
            else 
                ERROR("Could not build ranges for the " .. devName)
            end 
            -- tprint(deviceData.group)
        end 
        scanCounter = scanCounter + 1 
    end 
    
    if (scanCounter == VERY_FIRST_SCAN) then 
        DEBUG("First scan, will read all!")
        scanCounter = scanCounter + 1 
        return 
    end 
    
    -- GROUP READ -----------------------------------------------
    if (scanCounter >= SECOND_SCAN) then 
        
        DEBUG("scanCounter > 2 ...")
        for dname, ddata in pairs(readCache) do 
            
            for gr, addrList in ipairs(ddata.group) do 
                DEBUG("Making group# " .. gr .. " read for " .. dname )
                
                local wordCount = #addrList
                local packetMade = makeReadPacket(DEVICE_NODE, dname, addrList[1], wordCount)
                
                if packetMade then 
                    sendString(packetMade)
                    local response = readReply()
                    if (not response)  then 
                       ERROR("Could not read response!")
                    else 
                       local payloadEndPosition = WORD_DATA_START_POS + wordCount * 4 - 1  
                       if (not validate(response, DEVICE_NODE
                                        , READ_COMMANDS[dname]
                                        , payloadEndPosition) )      then 
                           ERROR("Could not validate group read reply")
                           break 
                       else 
                           -- STORING DATA IN CACHE --------------
                            for w = 1, wordCount do 
                                local dataOffset = WORD_DATA_START_POS + (w - 1) * 4 
                                local data = getNumberFromASCII(HEX_BASE, unpack(table.sub(response
                                                                          ,dataOffset
                                                                          ,dataOffset + 3)))    
                                ddata.stored[addrList[w]] = data 
                            end 
                       end 
                    end 
                else 
                    ERROR("could not make packet!")
                    break 
                end -- packet made 
                DEBUG("finished group read!")
            end -- addr list 
        end -- dname, ddata 
    end 
end 
-- end of protocol sample
</code>

For full text protocol or more features, turn to your WebHMI supplier. 

In the connection properties, select this newly created protocol:

{{ :conn:conn-examples:omron-conn-property-1.png?direct&800 |}}

And set communication paramteres:

{{ :conn:conn-examples:omron-conn-property-2.png?direct&800 |}}