EEPROM health monitor, code optimization

Author: budulinek

README.md

@@ -30,7 +30,8 @@ Change settings of your Arduino-based Modbus RTU to Modbus TCP/UDP gateway via w
   - send Modbus request and recieve Modbus response
   - scan Modbus slaves on RS485 interface
   - queue (buffer) status
-  - error counters (stored in EEPROM)
+  - counters ("RTU Data", "Ethernet Data", "Modbus Statistics") are periodically saved to EEPROM (every 6 hours)
+  - unsigned longs are used, rollover of counters is synchronized
   - content of the Modbus Status page is updated in the background (fetch API), javascript alert is shown if connection is lost
 * optimized TCP socket management (web interface and Modbus TCP):
   - gateway always listens for new web and Modbus TCP connections
@@ -57,6 +58,10 @@ Change settings of your Arduino-based Modbus RTU to Modbus TCP/UDP gateway via w
 
 **Reboot**.
 
+**EEPROM Health**. Keeps track of EEPROM write cycles (persistent, never cleared during factory resets)
+
+**Ethernet Sockets**. Max number of usable sockets. See Limitations bellow. One socket is reserved for Modbus UDP, remaining sockets are shared between Modbus TCP and WebUI.
+
 **Generate New MAC**. Generate new MAC address. First 3 bytes are fixed 90:A2:DA, remaining 3 bytes are true random.
 
 <img src="/pics/modbus2.png" alt="02" style="zoom:100%;" />
@@ -73,7 +78,7 @@ Change settings of your Arduino-based Modbus RTU to Modbus TCP/UDP gateway via w
 
 **Requests Queue**. Monitors internal request queue (buffer). The limits for bytes and for the number of requests stored in the queue can be configured in advanced settings.
 
-**Modbus Statistics**. Counters for various errors. Counters are periodically saved to EEPROM. Insigned longs are used, rollover of counters is synchronized:
+**Modbus Statistics**.
 * **Slave Responded**. Slave responded with a valid Modbus RTU response within response timeout.
 * **Slave Responded with Error (Codes 1~8)**. Slave responded, but with an error. For the list of error codes see https://en.wikipedia.org/wiki/Modbus#Exception_responses.
 * **Gateway Overloaded (Code 10)**. Request queue is full (either the number of bytes stored or the number of requests stored). Request was dropped and the gateway responded with an error code 10.
@@ -148,14 +153,15 @@ Get the hardware (cheap clones from China are sufficient) and connect together:
 * **Arduino Nano, Uno or Mega** (and possibly other). On Mega you have to configure Serial in advanced settings in the sketch.
 * **W5100, W5200 or W5500 based Ethernet shield**. The ubiquitous W5100 shield for Uno/Mega is sufficient. If available, I recommend W5500 Ethernet Shield. !!! ENC28J60 will not work !!!
 * **TTL to RS485 module**:
-  - with hardware automatic flow control (recommended, available on Aliexpress)<br>
-      Arduino <-> Module<br>
-      Tx1 <-> Tx<br>
-      Rx0 <-> Rx
-  - with flow controlled by pin (such as MAX485 module)<br>
-      Arduino <-> MAX485<br>
-      Tx1 <-> DI<br>
-      Rx0 <-> RO<br>
+  - recommended: TTL to RS485 module with hardware automatic flow control (available on Aliexpress)<br>
+      Arduino <-> Module
+      Tx1 <-> Tx
+      Rx0 <-> Rx<br>
+      
+  - not recommended: MAX485 module with flow controlled by pin (works but is vulnerable to burn outs)<br>
+      Arduino <-> MAX485
+      Tx1 <-> DI
+      Rx0 <-> RO
       Pin 6 <-> DE,RE
 
 Here is my setup:

arduino-modbus-rtu-tcp-gateway/01-interfaces.ino

@@ -54,29 +54,29 @@ void startSerial() {
 #endif                                             /* RS485_CONTROL_PIN */
 }
 
-// time to send 1 character over serial in microseconds
-unsigned long charTime() {
-  byte bits =                                                   // number of bits per character (11 in default Modbus RTU settings)
+// number of bits per character (11 in default Modbus RTU settings)
+byte bitsPerChar() {
+  byte bits =
     1 +                                                         // start bit
     (((localConfig.serialConfig & 0x06) >> 1) + 5) +            // data bits
     (((localConfig.serialConfig & 0x08) >> 3) + 1);             // stop bits
   if (((localConfig.serialConfig & 0x30) >> 4) > 1) bits += 1;  // parity bit (if present)
-  return (bits * 10000UL) / (unsigned long)localConfig.baud;
+  return bits;
 }
 
-// character timeout
+// character timeout in micros
 unsigned long charTimeOut() {
   if (localConfig.baud <= 192) {
-    return 1.5 * charTime();  // inter-character time-out should be 1,5T
+    return (15000UL * bitsPerChar()) / localConfig.baud;  // inter-character time-out should be 1,5T
   } else {
     return 750;
   }
 }
 
-// minimum frame delay
+// minimum frame delay in micros
 unsigned long frameDelay() {
   if (localConfig.baud <= 192) {
-    return 3.5 * charTime();  // inter-frame delay should be 3,5T
+    return (35000UL * bitsPerChar()) / localConfig.baud;  // inter-frame delay should be 3,5T
   } else {
     return 1750;  // 1750 μs
   }
@@ -94,11 +94,11 @@ void startEthernet() {
   memcpy(mac, MAC_START, 3);               // set first 3 bytes
   memcpy(mac + 3, localConfig.macEnd, 3);  // set last 3 bytes
 #ifdef ENABLE_DHCP
-  if (extraConfig.enableDhcp) {
+  if (localConfig.enableDhcp) {
     dhcpSuccess = Ethernet.begin(mac);
   }
-  if (!extraConfig.enableDhcp || dhcpSuccess == false) {
-    Ethernet.begin(mac, localConfig.ip, extraConfig.dns, localConfig.gateway, localConfig.subnet);
+  if (!localConfig.enableDhcp || dhcpSuccess == false) {
+    Ethernet.begin(mac, localConfig.ip, localConfig.dns, localConfig.gateway, localConfig.subnet);
   }
 #else  /* ENABLE_DHCP */
   Ethernet.begin(mac, localConfig.ip, {}, localConfig.gateway, localConfig.subnet);  // No DNS
@@ -119,7 +119,7 @@ void (*resetFunc)(void) = 0;  //declare reset function at address 0
 
 #ifdef ENABLE_DHCP
 void maintainDhcp() {
-  if (extraConfig.enableDhcp && dhcpSuccess == true) {  // only call maintain if initial DHCP request by startEthernet was successfull
+  if (localConfig.enableDhcp && dhcpSuccess == true) {  // only call maintain if initial DHCP request by startEthernet was successfull
     uint8_t maintainResult = Ethernet.maintain();
     if (maintainResult == 1 || maintainResult == 3) {  // renew failed or rebind failed
       dhcpSuccess = false;
@@ -148,7 +148,7 @@ void maintainUptime() {
 bool rollover() {
   // synchronize roll-over of run time, data counters and modbus stats to zero, at 0xFFFFFF00
   const unsigned long ROLLOVER = 0xFFFFFF00;
-  for (byte i = 0; i < ERROR_LAST; i++) {  // there is no counter for SLAVE_ERROR_0B_QUEUE
+  for (byte i = 0; i < ERROR_LAST; i++) {
     if (errorCount[i] > ROLLOVER) {
       return true;
     }
@@ -157,23 +157,23 @@ bool rollover() {
   if (seconds > ROLLOVER) {
     return true;
   }
-  if (serialTxCount > ROLLOVER || serialRxCount > ROLLOVER || ethTxCount > ROLLOVER || ethRxCount > ROLLOVER) {
-    return true;
+  for (byte i = 0; i < DATA_LAST; i++) {
+    if (rtuCount[i] > ROLLOVER || ethCount[i] > ROLLOVER) {
+      return true;
+    }
   }
 #endif /* ENABLE_EXTRA_DIAG */
   return false;
 }
 
 void resetStats() {
   memset(errorCount, 0, sizeof(errorCount));
-  statsEepromTimer.sleep(0);
 #ifdef ENABLE_EXTRA_DIAG
   remaining_seconds = -(millis() / 1000);
-  ethRxCount = 0;
-  ethTxCount = 0;
-  serialRxCount = 0;
-  serialTxCount = 0;
+  memset(rtuCount, 0, sizeof(rtuCount));
+  memset(ethCount, 0, sizeof(ethCount));
 #endif /* ENABLE_EXTRA_DIAG */
+  updateEeprom();
 }
 
 void generateMac() {
@@ -187,7 +187,25 @@ void generateMac() {
   }
 }
 
-
+void updateEeprom() {
+  eepromTimer.sleep(EEPROM_INTERVAL * 60UL * 60UL * 1000UL);  // EEPROM_INTERVAL is in hours, sleep is in milliseconds!
+  eepromWrites++;                                             // we assume that at least some bytes are written to EEPROM during EEPROM.update or EEPROM.put
+  int address = CONFIG_START;
+  EEPROM.put(address, eepromWrites);
+  address += sizeof(eepromWrites);
+  EEPROM.put(address, VERSION[0]);
+  address += 1;
+  EEPROM.put(address, localConfig);
+  address += sizeof(localConfig);
+  EEPROM.put(address, errorCount);
+  address += sizeof(errorCount);
+#ifdef ENABLE_EXTRA_DIAG
+  EEPROM.put(address, rtuCount);
+  address += sizeof(rtuCount);
+  EEPROM.put(address, ethCount);
+  address += sizeof(ethCount);
+#endif /* ENABLE_EXTRA_DIAG */
+}
 
 #if MAX_SOCK_NUM == 8
 unsigned long lastSocketUse[MAX_SOCK_NUM] = { 0, 0, 0, 0, 0, 0, 0, 0 };

arduino-modbus-rtu-tcp-gateway/02-modbus-tcp.ino

@@ -43,7 +43,7 @@ void recvUdp() {
   unsigned int msgLength = Udp.parsePacket();
   if (msgLength) {
 #ifdef ENABLE_EXTRA_DIAG
-    ethRxCount += msgLength;
+    ethCount[DATA_RX] += msgLength;
 #endif                               /* ENABLE_EXTRA_DIAG */
     byte inBuffer[MODBUS_SIZE + 4];  // Modbus TCP frame is 4 bytes longer than Modbus RTU frame
                                      // Modbus TCP/UDP frame: [0][1] transaction ID, [2][3] protocol ID, [4][5] length and [6] unit ID (address)..... no CRC
@@ -72,8 +72,8 @@ void recvUdp() {
       }
       Udp.endPacket();
 #ifdef ENABLE_EXTRA_DIAG
-      ethTxCount += 5;
-      if (!localConfig.enableRtuOverTcp) ethTxCount += 4;
+      ethCount[DATA_TX] += 5;
+      if (!localConfig.enableRtuOverTcp) ethCount[DATA_TX] += 4;
 #endif /* ENABLE_EXTRA_DIAG */
     }
   }
@@ -82,7 +82,7 @@ void recvUdp() {
 void recvTcp(EthernetClient &client) {
   unsigned int msgLength = client.available();
 #ifdef ENABLE_EXTRA_DIAG
-  ethRxCount += msgLength;
+  ethCount[DATA_RX] += msgLength;
 #endif                             /* ENABLE_EXTRA_DIAG */
   byte inBuffer[MODBUS_SIZE + 4];  // Modbus TCP frame is 4 bytes longer than Modbus RTU frame
   // Modbus TCP/UDP frame: [0][1] transaction ID, [2][3] protocol ID, [4][5] length and [6] unit ID (address).....
@@ -113,8 +113,8 @@ void recvTcp(EthernetClient &client) {
     }
     client.write(outBuffer, i);
 #ifdef ENABLE_EXTRA_DIAG
-    ethTxCount += 5;
-    if (!localConfig.enableRtuOverTcp) ethTxCount += 4;
+    ethCount[DATA_TX] += 5;
+    if (!localConfig.enableRtuOverTcp) ethCount[DATA_TX] += 4;
 #endif /* ENABLE_EXTRA_DIAG */
   }
 }
@@ -215,13 +215,13 @@ void deleteRequest()  // delete request from queue
 }
 
 void clearQueue() {
-  queueHeaders.clear();  // <- eats memory!
+  queueHeaders.clear();
   queueData.clear();
   scanReqInQueue = false;
   priorityReqInQueue = false;
   memset(socketInQueue, 0, sizeof(socketInQueue));
   memset(slaveStatus[SLAVE_ERROR_0B_QUEUE], 0, sizeof(slaveStatus[SLAVE_ERROR_0B_QUEUE]));
-  sendTimer.sleep(0);
+  sendMicroTimer.sleep(0);
 }
 
 bool getSlaveStatus(const uint8_t slave, const byte status) {

arduino-modbus-rtu-tcp-gateway/03-modbus-rtu.ino

@@ -18,7 +18,7 @@
 
 
 void sendSerial() {
-  if (!sendTimer.isOver()) {
+  if (!sendMicroTimer.isOver()) {
     return;
   }
   if (queueHeaders.isEmpty()) {
@@ -62,7 +62,7 @@ void sendSerial() {
           txNdx = 0;
           mySerial.flush();
 #ifdef RS485_CONTROL_PIN
-          // sendTimer.sleep(frameDelay());  // Short delay before we toggle the RS485_CONTROL_PIN and disable RS485 transmit. Not needed if we use flush()
+          // sendMicroTimer.sleep(frameDelay());  // Short delay before we toggle the RS485_CONTROL_PIN and disable RS485 transmit. Not needed if we use flush()
 #endif /* RS485_CONTROL_PIN */
           serialState++;
         }
@@ -71,8 +71,8 @@ void sendSerial() {
     case 2:  // DELAY:
       {
 #ifdef ENABLE_EXTRA_DIAG
-        serialTxCount += myHeader.msgLen;
-        serialTxCount += 2;
+        rtuCount[DATA_TX] += myHeader.msgLen;
+        rtuCount[DATA_TX] += 2;
 #endif
 #ifdef RS485_CONTROL_PIN
         digitalWrite(RS485_CONTROL_PIN, RS485_RECEIVE);  // Disable RS485 Transmit
@@ -82,7 +82,7 @@ void sendSerial() {
         queueHeaders.unshift(myHeader);
         unsigned long delay = localConfig.serialTimeout;
         if (myHeader.requestType & SCAN_REQUEST) delay = SCAN_TIMEOUT;  // fixed timeout for scan requests
-        sendTimer.sleep(delay * 1000UL);
+        sendMicroTimer.sleep(delay * 1000UL);
         serialState++;
       }
       break;
@@ -131,10 +131,10 @@ void recvSerial() {
       serialIn[rxNdx] = b;
       rxNdx++;
     }  // if frame longer than maximum allowed, CRC will fail and errorCount[ERROR_RTU] will be recorded down the road
-    recvTimer.sleep(charTimeOut());
-    sendTimer.sleep(localConfig.frameDelay * 1000UL);  // delay next serial write
+    recvMicroTimer.sleep(charTimeOut());
+    sendMicroTimer.sleep(localConfig.frameDelay * 1000UL);  // delay next serial write
   }
-  if (recvTimer.isOver() && rxNdx != 0) {
+  if (recvMicroTimer.isOver() && rxNdx != 0) {
     // Process Serial data
     // Checks: 1) CRC; 2) address of incoming packet against first request in queue; 3) only expected responses are forwarded to TCP/UDP
     header myHeader = queueHeaders.first();
@@ -158,7 +158,7 @@ void recvSerial() {
       errorCount[ERROR_RTU]++;
     }
 #ifdef ENABLE_EXTRA_DIAG
-    serialRxCount += rxNdx;
+    rtuCount[DATA_RX] += rxNdx;
 #endif /* ENABLE_EXTRA_DIAG */
     rxNdx = 0;
   }
@@ -182,25 +182,24 @@ void sendResponse(const byte MBAP[], const byte PDU[], const int pduLength) {
     }
     Udp.endPacket();
 #ifdef ENABLE_EXTRA_DIAG
-    ethTxCount += pduLength;
-    if (!localConfig.enableRtuOverTcp) ethTxCount += 4;
+    ethCount[DATA_TX] += pduLength;
+    if (!localConfig.enableRtuOverTcp) ethCount[DATA_TX] += 4;
 #endif /* ENABLE_EXTRA_DIAG */
   } else if (myHeader.requestType & TCP_REQUEST) {
     byte sock = myHeader.requestType & TCP_REQUEST_MASK;
     EthernetClient client = EthernetClient(sock);
-    //    if (W5100.readSnSR(sock) == SnSR::ESTABLISHED && W5100.readSnDPORT(sock) == myHeader.remPort) {  // Check remote port should be enough or check also rem IP?
-    if (W5100.readSnSR(sock) == SnSR::ESTABLISHED) {  // Check remote port should be enough or check also rem IP?
+    if (W5100.readSnSR(sock) == SnSR::ESTABLISHED && W5100.readSnDPORT(sock) == myHeader.remPort) {  // Check remote port should be enough or check also rem IP?
       if (localConfig.enableRtuOverTcp) client.write(PDU, pduLength);
       else {
         client.write(MBAP, 6);
         client.write(PDU, pduLength - 2);  //send without CRC
       }
 #ifdef ENABLE_EXTRA_DIAG
-      ethTxCount += pduLength;
-      if (!localConfig.enableRtuOverTcp) ethTxCount += 4;
+      ethCount[DATA_TX] += pduLength;
+      if (!localConfig.enableRtuOverTcp) ethCount[DATA_TX] += 4;
 #endif /* ENABLE_EXTRA_DIAG */
     }  // TODO TCP Connection Error
-  }    // else SCAN_REQUEST (no ethTxCount, but yes delete request)
+  }    // else SCAN_REQUEST (no ethCount[DATA_TX], but yes delete request)
   deleteRequest();
 }